The Alien Parasite Hypothesis


 * Leonard: We get it! 73 is the of numbers.
 * Sheldon: Chuck Norris wishes.


 * Howard: Let me ask you a question. What are you most afraid of?
 * Raj: I don't know. . Accidentally being buried alive. Any of those movies where you get a phone call that says you're going to die, and then you do.


 * Amy: HOO! (Often repeated)


 * Amy: Penny's friend, Zack, stopped by and said "hello" and I said "hoo!"
 * Sheldon: Hoo?
 * Amy: Zack.
 * Sheldon: Then why did you ask?
 * Amy: Ask what?
 * Sheldon: Who?
 * Amy: Zack.
 * Sheldon: All right, let's start over. What did you say when Zack walked in?
 * Amy: Hoo!
 * Sheldon: Zack.
 * Amy: Why do you keep saying 'Zack'?
 * Sheldon: Because you keep saying 'Who'.
 * Amy: I'm not saying 'hoo' now. I said 'hoo' last night.
 * Sheldon: And the answer was Zack, correct?
 * Amy: There was no question; I simply said "Hoo!"
 * Sheldon: [short pause] All right. I think I have enough to go on.