THE BIG BANG THEORY INSIDE JOKES ― "S10"

Alphabetized By Kimberly Potts

Tuesdays are thai takeout night. Photo: Michael Yarish/CBS 

They love comic books, costumes, video games, and sci-fi in all forms of media, but what are the other recurring themes, jokes, and life experiences that make up Sheldon, Leonard, Howard, Raj, Penny, Amy, Bernadette, Stuart, and their Big Bang Theory characters we’ve been following for nine seasons? Just as each of those characters can be largely defined by his or her eccentricities (we could write a book on Sheldon alone), some of those quirks also point to how much each of them has evolved throughout the seasons (even if some of them still have a significant way to go). Here’s our rundown. 

“Soft Kitty” 

The sweet lullaby Sheldon’s mom used to sing to him when he was sick. He makes Penny sing it to him for the first time in season one’s “The Pancake Batter Anomoly” — after he teaches it to her — and he goes on to sing it himself for a sick Penny (including a version in a round) and an ailing Professor Proton. Everyone, now: “Soft kitty, warm kitty / Little ball of fur / Happy kitty, sleepy kitty / Purr, purr, purr.”