Dr. Cuddy: You don't take Vicodin because you're scared. You take it so you won't feel pain. Everything you've ever done is to avoid pain. Drugs, sarcasm... keeping everybody at arm's length so no one can hurt you.
House: As opposed to everyone else in the world who goes looking for pain like it's buried treasure?
Dr. Cuddy: Pain happens when you care. Y-you can't love someone without making yourself open to their problems, their fears. And you're not willing to do that.