Leonard: I'm gonna get some coffee. You want some?
Sheldon: Uh, you're really going to have caffeine in front of me when I'm trying to get my life back on track?
Leonard: Uh, okay, let's pretend you do have a problem.
Sheldon: I do.
Leonard: You don't.
Sheldon: Yeah, but I do.
Leonard: No, you don't! But let's say you do. And don't say you do, because you don't! Now, wouldn't you think that throwing yourself into your work would be the best way to deal with it?
Sheldon: With what?
Leonard: Your problem.
Sheldon: I thought I didn't have a problem.
Howard: That was painful to watch.

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: No, I know, but plenty of things are addictive after a single exposure. I mean, crack cocaine, nicotine, Pringles. You know, once one pops one just can't stop.

Howard: It's pretty late. You think I've got time to run some more simulations on the cooling system?
Leonard: Sure, I'm still figuring out the thermo-acoustic expander.
Sheldon: Oh, while you do that I am going to pump cerebral spinal fluid through my brain cells to remove the metabolic by-products of the day's thoughts.
Howard: What?
Sheldon: It's called sleep and it's my bedtime. Nighty-night, y'all.

Penny: Now Sheldon's popular? What is happening?!