I too grew up when helmets were very rare, and I remember my brothers first uvex helmet, OMG! what an ugly thing it was.
But despite this he still wore it. Fortunately we now have some excellent designs.
I would never cycle without one myself as I like my head the way it is, with the brains and bones on the inside, covered by skin!
I know some people that argue they don't go fast enough to wear a helmet. I explain that speed has nothing to do with it, other than a whole lot more damage will be done at higher speeds, all over your body!
I read an article once, by a cyclist who now wears a helmet all the time as his female friend now lives in a wheel chair and is fed through a straw.
The reason she ended up in this state was not down to speed, or a car hitting her, she was actually stationary. She had just stopped at some lights and gotten her wheel stuck in a crack in the road, she tried to release her cleats but could't and just fell towards the path. Her head hit the curb side and the damage was done, needless to say, she wasn't wearing a helmet, and she was an experienced cyclist. It's a pretty non descript accident, happens to lots of cyclists falling off due to cleats not releasing, and they get away with it, unfortunately this poor woman didn't, and it only takes that one time.
At the end of the day it is a personal choice and hasn't been made law (as yet).