Season 8, Episode 13 - The Anxiety Optimization
Aired January 29, 2015
When Sheldon struggles to achieve a breakthrough in the field of dark matter, he decides his work environment is too comfortable and sets out to create a state of productive anxiety. Sheldon challenges his friends to irritate him and keep him on edge, but Sheldon is not the only one riled by his newfound thirst for discomfort. Meanwhile, the gang enjoy playing a new game that Howard invented, "Emily or Cinnamon?", which proves embarrassing for Raj.