17 ways Young Sheldon connects to The Big Bang Theory: From childhood quirks to iconic catchphrases
After The Big Bang Theory was released in 2007, fans were eager for more.
And they got it!
Stream Young Sheldon for free on 9Now.
A decade later in 2017, the prequel spin-off Young Sheldon was born and provided the backstory to the eccentric scientist Sheldon Cooper.
Jim Parsons played Sheldon in TBBT, while Iain Armitage took on the role in Young Sheldon... and fans completely fell in love with both.
Parsons even made a special appearance in the final ever episode of Young Sheldon in May 2024, delighting fans across the globe.
To celebrate the two, we've collated 17 times Young Sheldon connected to The Big Bang Theory; from habits and catchphrases to unexpected cameos.
Scroll through to see!
2. The start of Sheldon's 'roommate agreement'
The infamous roommate agreement with Leonard Hofstadter (Johnny Galecki) found its roots in Young Sheldon, where Sheldon began drafting overly detailed contracts for his siblings and family.
3. Kaley Cuoco's cameo on Young Sheldon as… pool water
If you thought the voice of Penny was never to be heard on Young Sheldon, then you would be wrong.
In the Season 3 episode titled 'Teenager Soup and a Little Ball of Fib', young Sheldon was plagued by nightmares about his upcoming swimming test, and featured a mysterious talking pool.
That voice was... you guessed it!
"That was absolutely the voice of Kaley as pool water," series co-creator Steve Molaro confirmed to TV Line.
"I needed someone to do the voice. I knew I wanted it to be female and kinda sexy, and I said, 'Well, duh! Kaley is perfect for this'," he explained.
What a connection!
4. Sheldon's iconic "Bazinga" catchphrase
In Young Sheldon, Sheldon's love for practical jokes is explored – culminating in his first utterance of the word "Bazinga."
This catchphrase became a hallmark of his character in The Big Bang Theory.
The prequel showed how young Sheldon's mischievous nature sparked the famous phrase.
5. The development of Sheldon's 'Soft Kitty' comfort song
Fans of The Big Bang Theory recognise 'Soft Kitty' as Sheldon's ultimate comfort tune, which he often made Penny (Kaley Cuoco) sing to him.
In Young Sheldon, his mother sang it to him during tough moments, giving emotional context to why it soothes adult Sheldon.
Here's another tidbit of information...
On The Big Bang Theory, Sheldon's mother Mary Cooper is played by Laurie Metcalf. On Young Sheldon, Sheldon's mother is played by Zoe Perry.
The link here? Zoe Perry is Laurie Metcalf's real-life daughter. That's one way to ensure a family resemblance.
6. The introduction of Meemaw
Sheldon often spoke about his beloved Meemaw in The Big Bang Theory.
In the prequel, audiences got to meet her in the form of Annie Potts' feisty, caring portrayal, showing why she was such a crucial figure in Sheldon's upbringing.
7. Sheldon's fondness for Professor Proton
Both series highlight Sheldon's admiration for Professor Proton, a children's science TV host.
Young Sheldon expands on this by depicting Sheldon's initial fascination and his early scientific curiosity inspired by the show.
9. Sheldon's fear of birds
In The Big Bang Theory, Sheldon's ornithophobia led to comedic situations.
Young Sheldon revealed the origin of this fear, tying it back to an unsettling childhood encounter with a bird.
10. Sheldon's behaviours
Sheldon's behaviors – including his need for order and his "spot" on the sofa – were seen developing in Young Sheldon, offering a glimpse into the origins of his routines.
11. The origin of Sheldon's proposal to Amy
In a heartfelt moment in Young Sheldon, an older Sheldon reminisced about a lesson from his father, which ledto his decision to propose to Amy in The Big Bang Theory.
This subtle but powerful link connects both series in a poignant way.
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