from Nerve

ELLIOT (Pointing to her forearm.) That’s a nice scar you got there. SUSAN Thanks. ELLIOT How’d you get that? SUSAN Tricycle accident. ELLIOT Not recently, I hope. SUSAN (Suddenly intense) I think you’re the one who’s never really had a good kiss. A good kiss is like a knife. The best kiss I ever had hurt more than anything. It couldn’t help it. A really good kiss can’t help but hurt you ‘cause you give part of yourself away. Make yourself vulnerable to it. A kiss, a real kiss severs nerves and cuts through you and that’s an injury you’ll never recover from.