I got my butt busted pretty good about 10 years ago - I was on my way to teach a class, and got left-hooked by a minivan. I made it an hour and a half through the class before horrible pain led me to visit the university clinic, where they basically told me that I could pay out of pocket to go to a real hospital or just deal with it. Being a poor grad student, I did the latter - not much can be done for a swollen butt or broken ribs, anyway.

It was a good two weeks before I could sit like a normal person on much of anything, including a bike.