What's the story behind one of your scars?

only got a few scars on 1 leg and its from a custom built trike my father had built. if you dont know what a trike is, it pretty much is a motorbike but with 2 wheels at the back and 1 at the front. my leg ended up slipping off where it was ment to rest and it got caught between the gears, i dont really know how to explain it but i essentially was getting my leg ripped up from the gears of the back 2 tires. my father had to crash into the side of me to stop it because by that point i had lost grip of the handle bars and was just getting a mangled leg