Leonard: Oh. Oh! I just thought of the murder weapon!
Penny: Swiss army knife?
Leonard: (laughs) No. [after Penny leaves] That's way better.

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.

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: 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.

Amy: So, you're just gonna sit here by yourself and do nothing?
Sheldon: Of course not. I'm going to write mean comments about Wil's show online.
Amy: Well, you can't criticize something you haven't seen.
Sheldon: I'm sorry, are you familiar with the Internet?

Sheldon: Oh, Amy. Good, you're here.
Amy: Hi. What's up?
Sheldon: How would you like to be on television?
Amy: Is it gonna be a news story where I have to say you were quiet and kept to yourself and I'm as shocked as anyone?

Wil Wheaton: [on TV] It's time for Professor Proton's science joke of the day. Why can you not trust atoms?
Sheldon: Hmm.
Wil Wheaton: [on TV] Because they make up everything.
Sheldon: Oh, that's funny! Yeah, because they do. They make up everything.