My first real crash up was when I was 13 and I had a Bonanza Minibike with a 2 HP Briggs & Stratton engine, the governor removed, and a centripetal metal shoe clutch. No suspension front or rear. And the only braking a rear scrub brake (paddle against rear tire).
I was zooming down the bumpy old Grouse Mountain logging road going about 30 MPH.
Suddenly the large center bolt that held the front fork assembly to the steering head unscrewed itself and came flying off. So the whole front fork, front tire and handle bars flipped away and started dragging under the bike by the throttle and brake cables.
The steering head dropped down onto the ground and I instantly went shooting forward on the dirt, my hands and knees grinding into the stones and dirt. I had to pick pieces of dirt and small pebbles out of my palms and knees for a few days and split a few finger nails. Yeeowwouch!