https://the-big-bang-theory.com/characters.Sheldon/
Sheldon Cooper is a theoretical physicist at Caltech who lives with his best friend, Leonard Hofstadter. Sheldon is known for his brilliant mind but also his quirky behavior and idiosyncrasies.
Sheldon has a hard time understanding sarcasm and is, with the exception of his close friends and girlfriend Amy, uncomfortable with most social situations. Sheldon is extremely logical, but this comes at a cost of often being rude of condescending to others. Although Sheldon's friends are often the subject of his put downs and narcissistic behavior, they have generally learned to live with Sheldon's quirks. Bernadette says that
Sheldon doesn't know when he's being mean as "the part of his brain that should know is getting a wedgie from the rest of his brain".