Big Bang Theory Quote
Sheldon: (Sheldon and Penny both have the flu) I just don't understand how this happened to me. I'm scrupulous about my hygiene, I regularly disinfect my hands, and I avoid contact with other people on general principle.
Penny: I don't know what to tell you, Sheldon.
(Sheldon remembers when he hugged Penny)
Sheldon: It's *you*! I touched *you*!
Penny: Happy Valentine's day.
Quote from S03E15 - The Large Hadron Collision