Sheldon: It's been three days. Why hasn't Stephen Hawking played a word?
Raj: The guy's a genius. Maybe you weren't challenging enough for him?
Sheldon: Not challenging? I was humiliating the man. I was thinking of writing a book called A Brief History of the Time I Made Stephen Hawking Cry Like a Little Girl.
Howard: There's the problem. You can't beat Hawking like that. He hates to lose. Everyone knows the guy's a big baby. I mean, forget the wheelchair, he should be in a stroller.

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.

Leonard: I did a bad thing.
Sheldon: Does it affect me?
Leonard: No.
Sheldon: Then suffer in silence.

Stephen Hawking: What does Sheldon Cooper and a black hole have in common? They both suck.

Sheldon: Steven Hawking's a genius and he talks like a robot. It's everything I ever wanted in a friend.