Two things, both on my long-gone Yammy DT400 a long time ago:
Flipped a wheelie - I loved riding wheelies and could hold that thing up for a few blocks. One night, after closing the restaurant where I worked, my co-workers challenged me to ride light to light on one wheel. I was beat, but tried it anyway. Sure enough, flipped it back over. Trashed the rear and front fenders and shredded up my work dress pants/shirt/tie. My license plate was into a small, metal ball. One co-worker gave me a ride home on his moped (come to think of it, climbing on that nuts moped was #3 of stupid things..) My wife took one look at me and just shook her head. I rolled the license plate to her across our kitchen table. That episode did get me a new set of cool, plastic yellow YZ fenders...
Got made at the wife, after drinking and took off on the DT thru our town during the wee hours. Don't remember how I got home or how the heck I didn't crash. Someone was looking out for me on that night (1st & last time riding a bike drunk for me!).
#3 - with photo evidence. Riding the same DT across historic, "Burnside Bridge" at Antietam Battlefield. The road was closed to vehicular traffic. But guys with 70's curly-perms and Rush concert baseball t's were exempt. Note, MD was a "no helmet" state in those days. #4 - Try getting the rats-nest out of a curly perm after riding all day without a helmet..... Sadly, not an issue these days (but I wear a helmet anyway...).