As you may recall, the episode starts with Sheldon (Jim Parsons ... in by the American Psychiatric Association. The Big Bang Theory is streaming now on Max, and a box set of the complete series ...

So, to celebrate the yuletide season, we took a lot back at every Christmas episode of "The Big Bang Theory" to see which of Leonard, Sheldon, Howard, Raj, Penny, Amy, and Bernadette's holiday ...