Young Sheldon Easter Eggs: Every Nod To The Big Bang Theory (And Every Future Reveal) Across 7 Seasons

TVLine is taking stock of Young Sheldon's many nods, cameos and crossovers with its predecessor, The Big Bang Theory. 

First launched in September 2017, Young Sheldon filled in the details of Dr. Cooper's upbringing in Medford, Texas. The story started off in 1989, and was told from the point of view of a more mature Sheldon, "who is older now and seeing his parents in a different light for the first time," according to series co-creator Steven Molaro. This altered perspective afforded the spinoff an opportunity to chart its own path and occasionally diverge from Big Bang canon without ever disrespecting what preceded it. 

Whether you're familiar with the prequel or simply curious, the following guide provides a robust rundown of all the ways the single-camera offshoot paid homage to Big Bang, provided answers to some of our lingering questions — for starters, what's a Bazinga?! — and painted a clearer picture of Sheldon's relationship with his family, including his ill-fated father. 

You'll also find multiple Easter eggs, crossovers that took place after Big Bang's 2019 series finale, and details about Sheldon and Amy's future that were not disclosed on TV's longest-running multi-camera comedy.

Laurie Metcalf's real-life daughter, Zoe Perry, plays her prequel counterpart.

Lance Barber, who played Leonard's high school bully Jimmy Speckerman in The Big Bang Theory Season 5, Episode 11, plays Sheldon's father.

June Squibb originated the role of Sheldon's grandmother in The Big Bang Theory Season 9, Episode 14. Designing Women vet Annie Potts took over the role in Young Sheldon Season 1, Episode 3.

The Young Sheldon Season 4 finale established the family patriarch's potential fall from grace, planting the seeds for an extramarital affair between George and next-door neighbor Brenda Sparks. Seasons 5 and 6 continued to hint that something would happen, but the prequel pivoted come 13-year-old Sheldon's spring break in Season 6, Episode 18, which is when Sheldon told Penny he walked in on his father with another woman.

In Young Sheldon Season 7, Episode 4, it was revealed that Sheldon actually walked in on his father and mother — but he would never learn that it was Mary in costume, not another woman.

Sheldon's father's fate was predestined — and Young Sheldon never sugarcoated it. George's mortality first cast a shadow over the prequel in Season 1, Episode 3, when George suffered a minor heart attack. Then in Season 4, Episode 17, Sheldon acknowledged that George was living on borrowed time.

In Season 6, Episode 16, the prequel implied that George's eventual demise would mark the eventual end of the series — and that's precisely what happened. He died off screen in Season 7, Episode 12, and his funeral was held in Young Sheldon's penultimate episode. You can revisit our post mortem interview with Lance Barber and Zoe Perry below:

Brenda's son was established as Sheldon's childhood bully in The Big Bang Theory Season 3, and was referenced twice more, in Seasons 5 and 9. He made his on-screen debut in Episode 1 of the spinoff, when he taunted Sheldon with his pet chicken, Mathilda. Ultimately, though, Billy was portrayed as more of a nuisance than a tormentor, and never shoved a Mexican peso up Sheldon's nose — at least not on screen.

The boy genius was always loco for locomotives. In fact, the prequel's first episode opened on a close-up of Sheldon's model train set. ("I've always loved trains," Adult Sheldon said. "In fact, if my career in theoretical physics hadn't worked out, my backup plan was to become a professional ticket taker. Or a hobo.")

Sheldon loves to tell people that he has perfect pitch, which he discovered on Day 1 at Medford High. When it was suggested by music instructor Ms. Fenley — played by Melissa Tang, who previously guest-starred on The Big Bang Theory Season 9, Episode 2 as Mandy Chow — that he pursue music professionally, the 9-year-old answered, "No thank you. Musicians take drugs."

In the series premiere, we caught a glimpse of Bob Newhart's alter ego demonstrating how to power a clock using only a potato — sound familiar? And a signed photo of Arthur Jeffries hangs on Young Sheldon's bedroom wall. Come Season 4, Episode 11, Sheldon tries (and fails) to make friends at East Texas Tech by starting his very own club in honor of the children's TV personality.

Those who aren't familiar with Young Sheldon may not know that Dr. Cooper's childhood friend, whose adult counterpart made an appearance in The Big Bang Theory Season 12, Episode 4, was first seen on the prequel, not the other way around. On Big Bang, Tam and Sheldon lost contact after attending different colleges. His formal introduction came in Young Sheldon Season 1, Episode 2.

Following five appearances on The Big Bang Theory as Nurse Althea Davis, Watson guest-starred on two episodes of Young Sheldon as Nurse Robinson. She has also played a nurse on two other Chuck Lorre sitcoms: Two and a Half Men and Bob Hearts Abishola.

Suffice it to say, Watson is the glue that holds the Chuck Lorre Cinematic Universe together.

In Season 1, Episode 3, Young Sheldon declared that seeing 14-year-old Georgie behind the wheel of Meemaw's car was enough to convince him that he never wanted to operate a motor vehicle — hence his reluctance when Leonard & Co. tried to give him virtual driving lessons in The Big Bang Theory Season 2, Episode 5.

Tam is single-handedly responsible for inspiring Dr. Cooper's weekly visits to Stuart's comic book store. Sheldon's childhood bestie introduced him to comics in Season 1, Episode 4.

Long before Adult Sheldon explained to Penny why he had a designated couch cushion, Young Sheldon asked Tam to forfeit his seat in the Medford High cafeteria. ("It's complicated, just move," he demanded in Season 1, Episode 4.)

In Young Sheldon Season 1, Episode 6, Dr. Cooper informed us that the reason he chose a career in theoretical physics had nothing to do with his desire to unravel the inner workings of the universe. He just wanted to prove he was right to a condescending NASA employee who talked down to him during his freshman year of high school.

After sharing a piece of pumpkin pie with Howard in The Big Bang Theory Season 9, Episode 9, Musk made a cameo in Young Sheldon Season 1, Episode 6. The scene in question revealed that Musk found the answer for successfully landing a Space X rocket in Dr. Cooper's childhood notebook.

Long before Sheldon explained the Schrödinger's Cat thought experiment to Penny in The Big Bang Theory Season 1, Episode 17, he broke it down for George Sr. and Georgie in Young Sheldon Season 1, Episode 8.

Leonard isn't the only one who's had to put up with Sheldon's timetable for bowel movements. It was referenced by Mary in Young Sheldon Season 1, Episode 8, and was also a point of contention in Season 3, Episode 16 (see above).

Two years later, in Season 5, Episode 16, Sheldon's bathroom schedule was shown in full for the first time.

Our first glimpse at Sheldon's fandom came three decades before he'd appear in a documentary honoring the late Leonard Nimoy. In Young Sheldon Season 1, Episode 9, Shelly explained to Meemaw that "Spock is half-human and half-Vulcan [and] ashamed of his human side... That's why I identify with him." Little did he know that he'd one day be gifted a Cheesecake Factory napkin containing Nimoy's DNA.

Tam introduces Sheldon (and Billy) to Dungeons & Dragons in Young Sheldon Season 1, Episode 11 — a role-playing game he'd go on to play with Leonard, Howard and Raj, as well as Penny, Bernadette and Amy in one of the 20 Best Episodes of The Big Bang Theory.

Long before Penny reluctantly sang Sheldon's favorite childhood lullaby while applying vapor rub — counterclockwise, lest his chest hair mat! — Mary sang that soothing song to her germaphobic son in Young Sheldon Season 1, Episode 13.

In Young Sheldon Season 1, Episode 15, geology enthusiast Libby reveals that she thinks of Sheldon not as a friend, but as a kid she has to babysit. In turn, the boy genius sours on her chosen field of study, referring to it as a "hobby." (No offense, Bert!)

In the same episode, Mary says to Sheldon, "I bet when you grow up, you will be surrounded by lots of smart, wonderful friends," to which he replies, "I can't see that happening."

Long before Amy crossed any T's or dotted any I's, 10-year-old Sheldon drafted his very first social contract in Young Sheldon Season 1, Episode 22. The Cooper-Sturgis-Tucker Behavior Agreement clarified his own involvement in Meemaw's relationship with his mentor, Dr. John Sturgis. But wait, there's more...

As Meemaw and Dr. Sturgis signed and dated the aforementioned document, our narrator revealed some rather gigantic #Shamy news: "I would go on to draw up such contracts throughout my life, with roommates, with my wife... even with my own children," he said, confirming that he and Amy would go on to have kids (plural!) after the events of The Big Bang Theory.

Four years later, in the Season 5, Episode 16, Sheldon mentioned that Amy eventually stripped him of his comic book allowance so they could start a college fund for their children.

In Season 2, Episode 4, Young Sheldon attends a sleepover at Tam's house, where he is first introduced to Mystic Warlords of Ka'a.

On The Big Bang Theory, Sheldon wears a t-shirt with the number 73 sprawled across his chest. In Young Sheldon Season 2, Episode 8, his younger counterpart establishes that 73 is his favorite prime number.

Jerry O'Connell was introduced as Georgie's adult counterpart during The Big Bang Theory Season 11, Episode 23, at which point it was revealed that Sheldon's older brother owned a successful chain of tire stores. A few months later, in Season 2, Episode 8 of Young Sheldon, Georgie took a part-time job at Herschel Sparks' auto body shop and discovered an affinity for tires. The rest is history.

"If it's funny, it's a Bazinga!" That was the slogan for a novelty company introduced in Young Sheldon Season 2, Episode 10, which at long last revealed how Sheldon came up with his signature catchphrase.

Mayim Bialik's star-making role was referenced in Young Sheldon Season 2, Episode 11, when Sheldon's twin sister Missy pitched a number of potential boyfriends for her Cabbage Patch doll.

MISSY: "How do you think Celeste would look next to Joey Lawrence?"

SHELDON: "I don't know who that is."

MISSY: "He's Blossom's brother."

SHELDON: "I don't know who that is."

MISSY: "It's a show. She wears hats."

Little did Young Sheldon know that his sister was referencing his future wife. (Funnily enough, Big Bang also name-dropped Bialik three years before she was cast as Amy.)

Five years later, in Young Sheldon Season 7, Episode 12, Missy suggests that her brother will find a "smart, weird girlfriend" in California, to which he scoffs, "I have a girlfriend and her name is Science."

Years before Sheldon forced Penny to ponder the question "What is physics?" and documented his findings, the pint-sized brainiac posed an experiment not unlike Project Gorilla and used Missy as a test subject — also in Young Sheldon Season 2, Episode 11.

"Bazinga!" might be the catchphrase most commonly associated with Parsons' alter ago, but "I'm not crazy! My mother had me tested!" is a close second. Sheldon first alluded to said assessment in Young Sheldon Season 2, Episode 14, when Georgie asked Sheldon if he was crazy after his younger brother confronted a bully.

Young Sheldon Season 2, Episode 22 tied directly into The Big Bang Theory's series finale. Immediately after Sheldon accepted the Nobel Prize in physics, the prequel flashed back 28 years to reveal Sheldon invited the entire school over to listen to the 1991 Nobel Prize announcements. Unfortunately, no one showed.

"In that moment, I felt like a neutrino, destined to be alone forever," Adult Sheldon narrated. "Thankfully, I was wrong," he said, as younger versions of his future friends were shown, one by one, with Easter eggs aplenty....

The asthmatic Leonard was seen in his signature red robe with an inhaler on his desk.

Wyatt's "little slugger" had a baseball bat near her bedside. On her wall was a cowboy hat to represent Nebraska, as well as a poster of Los Angeles, suggesting that she already had dreams of becoming a star.

Howard was in his bedroom, donning his signature silk pajamas. To his right was a table of magic tricks and props. Mrs. Wolowitz also made a cameo, telling her son to "put away the fakakta game" and get to bed.

Howard's future wife had a microscope on her nightstand to represent her interest in microbiology. A trophy and sash represented her days as a child beauty-pageant contestant.

Raj was still in India. A stuffed tiger on his bed represented the Royal Bengal Tigers. The telescope to his right foreshadowed his future career as an astrophysicist.

Sheldon's future wife, seen in her signature nightgown, was up late reading her beloved Little House on the Prairie. (Watch the scene and read our post mortem.)

Years before a Lord of the Rings film prop threatened to tear him and his friends apart on The Big Bang Theory, Young Sheldon dove into the writings of J. R. R. Tolkien in Season 3, Episode 4, and had dreams where he, too, had transformed into Gollum.

TVLine was the first to confirm that Cuoco made an uncredited, voice-only cameo in Season 3, Episode 10, in which Sheldon had a nightmare where he was taunted by a bacteria-infested pool. She was the first of Jim Parsons' castmates from The Big Bang Theory to cross over to Young Sheldon. (Watch the scene and read our post mortem.)

It was during the events of Young Sheldon Season 3, Episode 12 that the "hot beverage of comfort" became Sheldon's "go-to method of dealing with someone in emotional distress — and it always worked," he said. Well, "except when my wife was in labor, where it was suggested that I throw it in my own face."

When George Sr. stumbled upon Sheldon making tea for fellow pint-sized genius Paige, he told his son that he was proud of him. That was all the reason Sheldon needed to continue with this method for years to come.

Sheldon revealed his favorite childhood meal — spaghetti with cut-up hot dogs — to Penny in The Big Bang Theory Season 3, Episode 20. As of Young Sheldon Season 1, Episode 12, the pasta dish is Sheldon's designated Thursday-night dinner. We'd see him attempt to make it for himself in Season 3, Episode 21, before Mary served it to the entire family in Season 5, Episode 4.

Long before Sheldon befriended the renowned theoretical physicist, he would score an all-expense paid trip to Pasadena, Calif., where he and George Sr. attended an (off-screen) lecture by his scientific hero.

In Young Sheldon Season 3, Episode 16, Sheldon and George Sr. visited his future alma mater, Caltech. In the tag scene, father and son stood in the doorway of the cafeteria, where Sheldon would one day convene with his good friends Leonard, Howard and Raj. (Watch the prophetic scene and read our post mortem.)

In The Big Bang Theory Season 2, Episode 1, a drugged-up Sheldon let slip to Leonard that Mary used to smoke in the family car. Her nasty habit carried over to Young Sheldon, first when Sheldon's mom was caught smoking in Season 3, Episode 21.

In Young Sheldon Season 3, Episode 21, Sheldon made a videotape to convince Mary to let him go to college. Behind him was a chalkboard, the writing on which mirrored the writing on the whiteboards used as a backdrop for Sheldon and Amy's long-running web series.

In Young Sheldon Season 4, Episode 1, Jim Parsons was reunited with Mayim Bialik, who reprised her role as Sheldon's wife, Dr. Amy Farrah Fowler, in an audio-only capacity....

In that same scene, as the Coopers gathered in the backyard to commemorate Sheldon and Missy's respective graduations, Sheldon the Narrator (voiced by Parsons) said that "it was the best graduation party I had been to... until we had one for my son, Leonard Cooper.

"I wanted his name to be Leonard Nimoy Cooper, but Amy wouldn't let me," he revealed. That's when Bialik chimed in as Sheldon's better half and said, "Be lucky I let you name him Leonard."  (Read our post mortem.)

In Young Sheldon Season 5, Episode 17 — aka the 100th episode — we'd come to learn that Leonard Jr. had taken up skateboarding, much to Shelly's chagrin. Meanwhile, in Season 7, Episode 14, we found out that Jr. played pee-wee hockey for the Pasadena Penguins.

Sheldon's mortal enemy was first referenced in Young Sheldon Season 4, Episode 11, when TV's erstwhile Wesley Crusher caught Missy's eye.

MISSY: "Wil Wheaton's cute."

SHELDON: "If you like him, you should watch Star Trek with me."

MISSY: "He's not that cute."

In Young Sheldon Season 4, Episode 13, a new tradition was born when Sheldon proposed a science-based car game to his mother: "I'll say an element starting with the letter A, then you repeat that and add one starting with the letter B." As our narrator would explain, this tradition "would eventually bring countless hours of joy to Leonard on our drives to work. Much like my mother, he never beat me."

Dr. Cooper first struggled to flash a grin in The Big Bang Theory Season 2, Episode 4, when Raj was profiled for People magazine. In Young Sheldon Season 5, Episode 4, Sheldon found it difficult to convince George Sr. that he was happy having his own bedroom, separate from twin sister Missy.

In Young Sheldon Season 5, Episode 6, Adult Sheldon revealed why he's always used an alternative word for sex. "Every culture has their taboos," he said. "In the Ukraine, it's rude to whistle in doors — and they're correct. Not a fan," he pointed out, reinforcing his no-whistling policy first cited in The Big Bang Theory Season 2.

"In our society, any discussion of human reproduction seems to be so upsetting that it causes chaos," he continued. "Even the word 'sex' provokes an uncomfortable reaction. I thought 'fornicate' might work, but that seemed too judgy."

It's at that point that the 11-year-old reached for his thesaurus and landed on the perfect word — "a word so bland and clinical that it would be impossible to take offense to it."

Helberg reprised his role as Howard Wolowitz (voice only) in Young Sheldon Season 5, Episode 7, which told the origin story of Sheldon's "complicated relationship with engineering." (Watch a clip here.)

After Teller recurred as Dr. Cooper's father-in-law Larry in The Big Bang Theory Seasons 11 and 12, Penn and Teller made a cameo in Young Sheldon Season 5, Episode 22 as dermatological duo Acne and Pus.

In Young Sheldon Season 5, Episode 22, Sheldon, on the precipice of adulthood, swapped his signature button-down shirt for his very first graphic tee: a red crew neck with a Flash emblem, not unlike the one he frequently wore on Big Bang. (Read our post mortem.)

In Young Sheldon Season 6, Episode 1, the Coopers arrived for Sunday service and took a seat in the back of the church — much to Sheldon's chagrin. When Missy asked her brother what was wrong, he answered, "We're nowhere near the acoustic sweet spot," which was first referenced in The Big Bang Theory Season 2. (Read our post mortem.)

It was established in Season 1 that Georgie would be married by 19... The Big Bang Theory series finale told us that Sheldon's older brother marries and divorces twice by the time he's 45... and the Young Sheldon spinoff is called... Georgie & Mandy's First Marriage.

In Young Sheldon Season 6, Episode 7, viewers were introduced to Mandy's parents, Jim and Audrey, who run a tire shop that would eventually employ Georgie. Will McAllister Auto & Tire eventually be rebranded as Dr. Tire?

In Young Sheldon Season 6, Episode 22, 13-year-old Sheldon and his mother Mary headed to Germany so that Sheldon could participate in a summer research program at the University of Heidelberg. The Big Bang Theory alluded to this trip in Season 1, when Sheldon told Penny that Mary accompanied him while he was a visiting professor at the Heidelberg Institute — only then, Sheldon said he was 15, not 13.

So, why rewrite history? Well, Sheldon's recollection of his stint in Germany predated Sheldon telling Bernadette's father that George died when he was 14 — a piece of dialogue that came in The Big Bang Theory Season 7 and is now considered canon.

When Sheldon told Penny about his trip to Germany on The Big Bang Theory, he said that his mother flew back to Texas to help his dad after their house slipped off cinder blocks. "It was tornado season, and it was an aluminum house," he explained. But clearly Sheldon's memory was a bit fuzzy, because it wasn't his childhood home that suffered the brunt of the damage in Young Sheldon Season 6, Episode 22; it was Meemaw's house that got destroyed in the storm.

Sixteen years after a brief (but memorable) turn in The Big Bang Theory Season 2, Episode 5 as a disgruntled DMV employee, Octavia Spencer appeared in Young Sheldon Season 7, Episode 10 as Meemaw's probation officer.

Sheldon's customary triple knock is first seen in Young Sheldon Season 7, Episode 12. (When Meemaw asks if that means she has to say "hello" three times, her grandson answers, "No, that would be crazy!")

After lending his voice for 140 episodes of Young Sheldon, Jim Parsons reprises his role from The Big Bang Theory in the prequel's series finale. His scenes take place several years following the events of Big Bang's 2019 series finale and reveal that the Nobel Prize winner has been hard at work writing his memoir.

His home office includes a number of Easter eggs — including, but not limited to: Sheldon's Nobel Prize, a framed photo of #Shamy in Stockholm, the DNA model, a Flash mug, a Rubik's Cube coaster... and the couch from Apt. 4A!

After lending her voice in Young Sheldon Seasons 4 and 5, Mayim Bialik reprises her role from The Big Bang Theory in the prequel's series finale.

In her scenes opposite Parsons, it is confirmed that Sheldon and Amy have a daughter. Her name is not revealed, but we know that she shares something in common with Amy's bestie. "Your daughter wants to take acting classes," she tells her husband, to which he replies, "I told you we never should have let Penny babysit."

The very last Easter egg is saved for Young Sheldon's very last scene. Upon arriving at the California Institute of Technology, Sheldon is approached by a professor who asks if he's lost. He's played by none other than UCLA professor David Saltzberg, an experimental particle physicist who served as a scientific consultant on both The Big Bang Theory and Young Sheldon for a combined 18 years, after he was first hired as a consultant on Big Bang's unaired 2006 pilot.