Leonard: Damn, I need my inhaler.
Penny: Just don't smoke.
Leonard: No, I went down the stairs too fast.

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Amy: What is this?
Sheldon: A functional MRI of my brain. I did Sudoku before they took it so I'd be ripped.
Amy: I love it. Thank you.
Sheldon: And it's not just an MRI. The orbitofrontal cortex is lit up because I was thinking of you.

Penny: Howard and Bernadette's kid might be born on your birthday. How cool is that?
Amy: Yeah, but I thought this baby was supposed to ruin their sex life, not mine.

Raj: Don't come to the hospital. We're headed home.
Penny: Oh, that was fast. Did she sneeze the baby out?