When 12-14 yrs old, my brother and I rode our dirt bikes on/around the farm with no helmets until another farm teenager we knew hit a dog that ran out in front of him at night (no helmet). He was in a coma for months. He is in his 40's now and still has partial paralysis and a distinct limp. Mom bought us both helmets right after that and we wore them all the time.
When I was 16, the neighbor down the road died when his motorcycle hit a utility pole (no helmet).
In 2009, I got T- boned by a driver that didn't see me. Crushed my right leg and had it amputated just above the knee. I believe that my helmet saved my life.
Like someone else said, I believe that people should have the right to ride without helmets if they sign a statement claiming they accept full responsibility. Riding a motorcycle is inherently risky and you are likely to get hurt in even a minor accident- but not wearing a helmet seems a little like a SWAT team member declining to wear a bullet proof vest on a raid.
PS- yes- I agree that it is frustrating when bugs fly into the helmet and crawl around/in your ears.