Leonard: I still can't believe Sheldon had a best friend we've never heard about.
Raj: Ooh, somebody's jealous.
Leonard: I'm not jealous.
Howard: Leonard, this is a safe space. It's okay to be vulnerable.
Leonard: All I'm saying is you know the timing of a fellow's bowel movements, you don't think there's a lot left to discover.

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Amy: I tried to ask him about it, and he invoked section three, article five of the marriage contract: beeswax, none of your.

Bernadette: Look, I think that's LeBron over there.
Penny: James?
Bernadette: No, LeBron Kershenbaum.

Amy: Who's Tam?
Sheldon: He was my best friend in the whole world growing up.
Amy: Really? Why have I never heard you mention him before?
Sheldon: Oh, of course I have. I'm sure I've mentioned him, like, five times this week.
Amy: I don't think you have.
Sheldon: Tam! Tam! Tam! Tam! Tam! There, it's only Thursday.
Amy: I didn't just drink the crazy milk, I bought the crazy cow.