What is a Pre-Existing Condition?

I was hitting the ski slopes when a bizarre accident occurred. While fumbling my way off a chair lift, another chair hit me from behind and knocked me out cold. I woke up with a headache, in a hospital bed and immediately called my insurance company.
After explaining what happened the insurance rep said, “We’re covering nothing on this claim. You hit yourself in the head with a chair on a ski lift. You’re an idiot. And that’s a pre-existing condition.”