Leonard: Sheldon, that was really rude.
Sheldon: I'm sorry. Amy is the one constant I can count on, and now she's changing.
Leonard: It's just a haircut and some clothes.
Sheldon: No, it's the last straw! I can't take any more! [elevator bell dings]
Penny: Can you believe it? They finally fixed the elevator.

Penny: At one point, they had me figure out how to get a banana out of a puzzle box.
Leonard: Wait, Sheldon gave me a banana in a box. He was testing me, too.
Penny: Unbelievable.
Leonard: And how could a chimp even solve that? That was impossible.
Penny: Really? You couldn't get it out?

Leonard: If I take it off, Sheldon wins.
Penny: Sweetie, every night you don't kill him in his sleep, he wins.

Sheldon: Woman, you are playing with forces beyond your ken.
Penny: Yeah, well your Ken can kiss my Barbie.

Amy: Oh. That's me. Hello? Yes, this is Dr. Fowler. I see. Okay, thank you. We won.
Penny: Congratulations!
Leonard: Oh, my God!
Sheldon: We did it.
Amy: I know. Can you believe it?
Sheldon: That's a good point. What if I'm dreaming? [Leonard slaps Sheldon] We won the Nobel Prize!

Sheldon: It's happening! [phone chimes] Unknown caller. It's got to be them.
Amy: Okay, put it on speaker.
Sheldon: Hello?
Amy: Hi.
Barry Kripke: Hello. This is Sweden calling. Is this Dr. Cooper and Dr. Fowler?
Sheldon: Yes.
Amy: Yeah.
Barry Kripke: Congratulations. It is my pleasure to inform you that you've won the Nobel Prize in being suckers!

Penny: So, I guess the only thing that actually stays the same is that things are always changing.
Sheldon: Interesting. So you're saying the inevitability of change might be a universal constant.
Penny: Well, there's a little more to it than that, but, yeah, sure.