I've come close to getting seriously hurt. Got run off the road once and bent my front forks after going over the handlebars.
Every other one was my fault. I was riding FAST down a steep hill and wasn't paying much attention when I realized a sharp curve at the bottom to the right.
Braking and leaning the bike like a MC race rider, I still went left lane and missed the guardrail by inches. If a car had been coming I would've died probably. Heart was in my throat for a mile after that one.
I think the soft knobbies saved me.