Big Bang Theory Quote
Penny: (after the tale of Saturnalia) Okay, well, thank you for that, but I got you and Leonard a few silly neighbor gifts, so I'll just put them under my tree.
Sheldon: Wait! You bought me a present?
Penny: Uh-huh.
Sheldon: Why would you do such a thing?
Penny: I don't know. 'Cause its Christmas?
Sheldon: Oh, Penny. I know you think you are being generous, but the foundation of gift giving is reciprocity. You haven't given me a gift. You've given me an obligation.
Howard: Don't feel bad, Penny, it's a classic rookie mistake. My first Hanukah with Sheldon, he yelled at me for eight nights.
Penny: Now, hey, it's okay. You don't have to get me anything in return.
Sheldon: Of course I do. The essence of the custom is that I now have to go out and purchase for you a gift of commensurate value and representing the same perceived level of friendship as that represented by the gift you've given me. It's no wonder suicide rates skyrocket this time of year.
Penny: Okay, you know what? Forget it. I'm not giving you a present.
Sheldon: No, it's too late. I see it. That elf sticker says, "To Sheldon." The die has been cast. The moving finger has writ. Hannibal has crossed the alps.
Howard: (Raj then whispers into Howard's ear then they both laugh) I know. It's funny when it's not happening to us.
Penny: (Exasperated) Sheldon, I am very, very sorry.
Sheldon: No. No, I brought this on myself by being such an endearing and important part of your life.
(Turning to Howard and Raj)
Sheldon: I'm going to need a ride to the mall.
Howard: It's happening to us.
Quote from S02E11 - The Bath Item Gift Hypothesis