From http://www.msnbc.msn.com/id/6379795/?GT1=5740 :
Ashlyn is among a tiny number of people in the world known to have congenital insensitivity to pain with anhidrosis, or CIPA — a rare genetic disorder that makes her unable to feel pain.
“Some people would say that’s a good thing. But no, it’s not,” says Tara Blocker, Ashlyn’s mother. “Pain’s there for a reason. It lets your body know something’s wrong and it needs to be fixed. I’d give anything for her to feel pain.”
I know I've wished I didn't feel pain at one time or another, but this is incomprehensible!