Riding my bike down a hill from a friends. 10 years old, not thinking clearly and decided it would be a great idea to hit an unreasonable speed going down. Brake failed, couldn't slow myself down in time, and ended up flying out on to a main road!
Took an impact from a sedan, broke pretty much three ribs, right arm and all the way down my right leg. A good four months in hospital, casted from top to bottom! Haha.. Thankfully I was young and healed up nicely within the year.