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.