The Big Bang Theory, episode 1:16
- Penny: Uh, Sheldon, I didnt see your present.
- Sheldon: Thats because I didnt bring one.
- Penny: Well why not?
- Howard: Dont ask.
- Sheldon: The entire institution of gift giving makes no sense.
- Howard: Too late.
- Sheldon: Lets say that I go out and I spend fifty dollars on you, its a laborious activity, because I have to imagine what you need, whereas you know what you need. Now I can simplify things, just give you the fifty dollars directly and, you could give me fifty dollars on my birthday, and so on until one of us dies leaving the other one old and fifty dollars richer. And I ask you, is it worth it?
- Howard: Told you not to ask.
- Penny: Well, Sheldon, youre his friend. Friends give each other presents.
- Sheldon: I accept your premise, I reject your conclusion.
- Howard: Try telling him its a non-optional social convention.
- Penny: What?
- Howard: Just do it.
- Penny: Its a non-optional social convention.
- Sheldon: Oh. Fair enough.