Leonard: If you had told anyone that you were going away on a train, by yourself, across the country, do you know what they would have said?
Sheldon: That I couldn't do it?
Leonard: Exactly. Right after they said 'yeah!'

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.

Leonard: [to a "smiling" Sheldon] We're here to see Koothrappali, not kill Batman.

Sheldon: I feel renewed. I'm ready to deal with any changes that come my way. [sees Penny] Your hair is different. You changed your hair. I can't take this. I'm out.

Dan: You're scared of Bernadette?
Penny: Yeah, kinda.
Dan: I thought it was just me! Everyone thinks she's so nice with the little squeaky voice!

Sheldon: Leonard, as soon as we get home, I want to have coitus with Amy. [checks for Amy's reaction] Okay, she can't hear.