I'm old enough to have grown up without helmets, so my perspective is probably effected by my age. I don't bother to wear a helmet when running errands, or sporting around my tiny sleepy rural village, which gets very little motor vehicle traffic. On a Sunday evening, I can ride for an entire hour, and maybe encounter one car passing me, or perhaps a piece of farm equipment. I never wear a helmet when it's over 85 degrees, because it feels like I'm stuck in a toaster oven.

I do normally wear a helmet when it makes a lot of sense to do so, such as my 30-mile round trip commute on a state highway. Tractor trailers sometimes pass me, and motorists who are more interested in their smart phones and than the safety of cyclists.