Penny: Okay, what just happened?
Leonard: I don't know. Between you playing chess like Bobby Fischer and Sheldon being okay with you in his spot, I'm guessing someone went back in time, stepped on a bug, and changed the course of human events.

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.

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

Leonard: My point is, while you're spending all this time on your own, building computers or practicing your cello, what you're really doing is becoming interesting. When people finally do notice you, they're gonna find someone a lot cooler than they thought. And for those of you that were popular in high school, it's over, sorry. Thank you. Congratulations.

Sheldon: Gotta run. (Looks down at scissors) But not with scissors, that would be unsafe.

Sheldon: Bongo solo!

Penny: Where are you going?
Sheldon: Wherever the music takes me, kitten.