Young Sheldon premiered Monday night and fans of The Big Bang Theory finally got to see how the 9-year-old version of Sheldon Cooper (Iain Armitage) and his show are different from the mothership -- and it's very different. Besides the obvious format difference (single-cam versus TBBT's multi-cam setup) and lack of laugh track, the tone is warmer. It's far more more like The Wonder Years than Two and a Half Men.

That being said, it definitely shares DNA with The Big Bang Theory. The clearest similarity is in the performances of Armitage and Zoe Perry, who plays Sheldon's mother Mary, a role originated by Laurie Metcalf on The Big Bang Theory (Perry and Metcalf literally share DNA; Metcalf is Perry's mother). Armitage, a very talented young actor, is already nailing grown-up Sheldon Jim Parsons' cadences. This precocious performance is completely different what he delivered in Big Little Lies, so it's clear Armitage has some serious range. And while Perry isn't doing an impression of her mother as Mary, she is clearly playing the same character. It's impressive, particularly this early on. It also means fans will have no trouble buying Armitage and Perry's Young Sheldon characters growing into their Big Bang versions.

But Young Sheldon's pilot has several other connections to The Big Bang Theory sprinkled throughout the episode beyond the obvious. They're a little subtle, too. Young Sheldon doesn't say "Bazinga," but devoted Big Bang Theory fans will have been able to spot these fun Easter eggs.

Iain Armitage, <em>Young Sheldon</em>, Jim Parsons, <em>The Big Bang Theory</em>Iain Armitage, Young Sheldon, Jim Parsons, The Big Bang Theory

Sheldon has perfect pitch. On Young Sheldon, Sheldon walks into the music room at his high school and begins playing the piano like a musician despite never having played piano before. The music teacher discovers that Sheldon is a natural. He has perfect pitch -- that is, the ability to recognize and reproduce the pitch of any note. It's a rare gift. Of course, when she encourages him to pursue music, he says no, because "musicians take drugs."

Sheldon's perfect pitch has appeared on The Big Bang Theory before.

Professor Proton. Professor Proton, played by comedy legend Bob Newhart, was the host of a children's science TV show who Sheldon idolized as a kid and who first made Sheldon want to become a scientist. Growing up, he wore a bowtie because that's what Professor Proton wore (he hadn't yet settled on his signature look of a superhero t-shirt over a long-sleeved t-shirt). When Sheldon got to meet Professor Proton in The Big Bang Theory's sixth season and tell him what he meant to him when he was going through hard times as a kid, it was one of Sheldon's sweetest, most human moments. Professor Proton passed away in a later appearance, so it was a really nice moment when young Sheldon was watching him on TV as he did one of his signature experiments -- making a potato clock.

Billy Sparks. Young Sheldon introduced Billy Sparks and his chicken Matilda (who Sheldon hilariously addresses as "Matilda Sparks"), Sheldon's neighborhood bullies. Sheldon holds a grudge against Billy Sparks into adulthood, as Billy Sparks is still on his enemies list (and Matilda once treed him). Thanks to reader Jill Robinson for pointing this one out.

Stephen Hawking. Young Sheldon has a poster of Stephen Hawking on his wall. Little does he know that he's going to grow up to be a close, personal friend to the world's most famous physicist. So close, in fact, that he had to ask for Hawking's blessing before proposing to Amy (Mayim Bialik). In a way, Stephen Hawking made two guest appearances in these premieres.

There will surely be many more references to The Big Bang Theory on Young Sheldon. We're going to have to wait awhile to see them, though -- Young Sheldon doesn't return until Thursday, Nov. 2.

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