Priya: So did you get to talk to Penny?
Leonard: Oh, yes. Indeed, I did.
Priya: And?
Leonard: She completely understood everything I said. Case closed.
Priya: Was she upset?
Leonard: Maybe, but that's not my problem. She's not my girlfriend, you are.
Priya: I hope you weren't cruel to her.
Leonard: Is the autumn cruel for letting the flowers die, or is that just nature's way?

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.

Penny: Oh, big deal. Not knowing is part of the fun.
Sheldon: "Not knowing is part of the fun." Was that the motto of your community college?

Rajesh: Why so glum, chum?
Sheldon: Apparently you can't hack into a government supercomputer and then try to buy uranium without the Department of Homeland Security tattling to your mother.

Sheldon: So, you're saying this is a regulation deck?
Howard: I'm saying believe in magic, you muggle.