Putting a single cylinder BSA motorcycle engine in a Sears mini bike frame was pretty stupid, but it sure was fun.
I had to weld 12 inches of railroad track rail on the front forks so it didn't go over backwards on the shifts.
Every time the engine fired it left a black patch.
Trying snow skiing by myself when I had never skied before was pretty dumb.
First shot down the hill I ate **** and twisted both knees because I didn't know about the tension needed for the releases so I couldn't walk, and had to lay on my stomach on the skies and pull myself back home a mile or so.
It wasn't a ski slope or anything like that as we lived in the Sierra Nevada mountains, and I just took off on my own.