Leonard: Do you realize I don't live with the woman I love because of you? No other reason. Just you.
Sheldon: Is that true?
Leonard: Yes, it's true. The last time I brought it up, you had an emotional breakdown, got on a train, and ran away.

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: Sheldon, we know this is a sensitive subject, and Leonard's not going to move out until you're ready.
Sheldon: What if you did it gradually?
Leonard: All right, how about we start with two nights a week I live with Penny?
Sheldon: How about one night and I let you whistle?
Leonard: Okay.
Sheldon: When I'm not home.

Bernadette: Are you okay?
Raj: No, I'm not okay. I feel like I'm going to jump out of my skin.
Bernadette: I told you not to wax down there. It's itchy when it grows back.

Penny: Do I really force you to do things you don't want to?
Amy: Yeah, but it's okay.
Penny: How is it okay?
Amy: I promised myself if I ever got friends I'd do whatever they said. Really, I'm lucky you found me before a cult did.