"I would if I could but I can't so I shan't." I quote Sheldon off the Big Bang theory.

Sheldon: Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and as it always has, rock crushes scissors.

Sheldon: I'm not insane. My mother had me tested!

Sheldon: I made tea. 
Leonard: I don't want tea. 
Sheldon: I didn't make tea for you. This is my tea. 
Leonard: Then why are you telling me? 
Sheldon: It's a conversation starter. 
Leonard: That's a lousy conversation starter. 
Sheldon: Oh, is it? We're conversing. Checkmate.

Sheldon: Stop it both of you! All this fighting, I might as well be back with my parents! 
*Imitating his Mom* Dammit George! I told you if you didn't quit drinking I would leave you! 
*Imitating his Dad* Well, I guess that makes you a liar, because I'm drunk as hell and you are still here! 
*Imitating his Mom* Stop yelling, you're making Sheldon cry! 
*Imitating his Dad* I'll tell you what is making Sheldon cry, that I let you name him SHELDON!

Sheldon: I'd like to go over some proposed changes to the roommate agreement, specifically to address Penny's annoying personal habits.
Penny: Oh my God! What personal habits?
Sheldon: I have a list. FYI overuse of the phrase &quote;Oh my God&quote; is number 12.