The Big Bang Theory prequel spin-off series Young Sheldon ended with a heartfelt, two-episode finale. Throughout its run, Young Sheldon featured plenty of Easter Eggs and references to The Big Bang Theory. Many episodes depicted events that adult Sheldon (Jim Parsons) had recalled to his friends through TBBTs 12-season run, including ones he remembered accurately and those he didnt. These ranged from the origins of his favorite word, Bazinga! to his fathers alleged affair, why he always knocks three times, and that time his parents “had him tested.”