Raj: Well, that's the lecture for today. Uh, let's open it up for questions. Uh- Oh, you! Sir, yes. You have a question?
Howard: Yeah. Actually, I have a two-part question.
Raj: Are you sure? I get the sense it's only one part.
Howard: No, no, it's two. Part one: the new star you were talking about. How long did it take that light to reach Earth? And part two: is it true you plant your friends in the audience to ask questions?
Raj: 46,000 years. And no, I don't plant my friends, because apparently, I don't have any.

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.

Amy: Wow. Déjà vu.
Sheldon: Amy, you're a neuroscientist. you know the latest research into déjà vu suggests it's nothing but the frontal regions of the brain attempting to correct an inaccurate memory.
Amy: You telling me stuff I already know is definitely déjà vu.

Sheldon: How can I tell if I'm doing something for a noble reason or a selfish reason?
Amy: Try saying the thing in your head and see if you can add the words, "That'll show 'em."

Sheldon: Leonard's about to demand a job that I don't think the university will give him. I'm worried he's making a giant mistake. But maybe I only think that because deep down I don't want him to succeed.
Amy: The fact that you're worried about your motivation supports the idea that you genuinely care for your friend.
Sheldon: I do. Thank you, Amy. You know what? After I've talked to Leonard, you've earned yourself a bonus lecture on Sponge Hulk.
Amy: That'll show me.