At the beginning of last summer I had to dodge a car that pulled out and got caught up in some trolly tracks on the road sending me diagonally over the bars and headfirst into the ground. I was wearing a helmet which took a good amount of damage, my neck was extremely stiff for a week or so but otherwise I was fine. Without my helmet, the damage from that crash would have gone to my head which at the very least would have caused a great deal of discomfort.

I'm not interested in getting into the debate as to whether helmets are always effective, or whether everyone should wear one or anything like that. I simply know that in one particular instance I walked away more or less uninjured because I was wearing my helmet and had I not been wearing one, I almost certainly would have had a solid concussion or worse. So I always wear one at any rate.