Over the years I've chosen to ride with and without helmets. Have pretty much gotten used to the one I own. Still, riding without one is much more pleasant.
February, this year, while at home, I became sick with what I believe may have been restaurant food poisoning - at any rate got up in the middle of the night to go to the bathroom, thinking I may have to throw up again. I never made it. Somewhere down the hall, I passed out, fell backwards and my head hit the tile flooring. I was unconscious.
Following a copter ride to the nearest trauma center, and three days in intensive care, I was discharged with what was called Subdural Hematoma - blood pooling on the brain. It's taken me six months to recover.
So now, thinking about helmets, I believe I'd be afraid to ride again without one. With what I experienced, in home, I'd hate to see what a fall on the road might do. I never realized just how sensitive the brain area is.
Hope none of you ever have to experience that for yourself.