OK I'll start. This is a true story. I will never forget it.
About ten years ago, I was training at a gym in Las Vegas while I was there visiting family.
I saw a dude on the treadmill right in front of me, running his ass off on a very steep incline. It was ridiculous...prolly one of the highest grade inclines on the machine, going about 9 mph or more.
He slipped, fell, and hit the treadmill, which shot him off the back end and he slammed into the stairmaster I was on behind him.
He got up, covered in "road rash," and decided to try to play it cool...like he wasn't embarassed at all. You all know the type...he shook it off, laughed a little with his friend who was on the teadmill next to him, and he decided that the best approach would be to run back on to the treadmill while it is going full speed uphill.
Needless to say, at that speed and with a 15 degree incline, that didn't work. As he tried to run back up the treadmill, he missed his step or didn't catch the pace or something...
He slipped, fell, and got shot off the back end of the treadmill and smashed into my stairmaster again. At this point, he was bloodied on both legs and thought better of getting back on. His friend had to stop running so that he could double over with laughter.