Leonard: If it's not tangible, how do you know it's not just gonna vanish tomorrow?
Howard: Really? You're dating Penny, and you're gonna poke at something that could vanish tomorrow?

Howard: You know, I'm really glad you decided to learn Mandarin.
Sheldon: Why?
Howard: Once you're fluent, you'll have a billion more people to annoy instead of me.

Bernadette: Maybe we should get one of those machines to help her up the stairs.
Howard: You mean a forklift?

Sheldon: Sheldon Cooper does not cry.
Howard: That's true, you'd rust.

Sheldon: Oh, Stuart, good. I was wondering, will you be accepting Bitcoin?
Stuart: Well, I don't know what that is, but it's got "coin" in it, and my cash register doesn't, so yeah.

Mrs. Wolowitz: Howard, what's going on?! Are you boys roughhousing?!
Howard: No, we're not roughhousing! We're scientists! Scientists don't roughhouse!
Mrs. Wolowitz: Excuse me, Mr. Grown-up!

Mrs. Wolowitz: Howard, I made cookies for you and your little friends!
Howard: They're not my little friends, and we don't want cookies!
Leonard: Actually, a cookie sounds good.
Howard: All right, we'll have cookies! Thank you very much!