Penny: Maybe there's something in the book that will help.
Leonard: Worth a shot.
Penny: Okay. Let's see, let's see. "Biting other children"?
Leonard: Well, sometimes, but problem for another day.

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.

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.

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

Penny: No, I've been reading Bernadette's parenting book. It's like the answer key to the Sheldon test.

Leonard: It's fine, I've been driving him for years. What's one more day?
Sheldon: Oh, and I've got a new car game we can play. It's called "What siren am I?"

Sheldon: All right, you ready for your next one? Just a warning, this one's a little annoying. (imitates a high-pitched siren)
Leonard: Let's take a little little break, I'm getting a headache.
Sheldon: Aw, right in the middle of our fun game.
Leonard: Yeah, weird.