I do, but I guess it depends on where you ride, how often, and how aggressive you are when you do ride. Just like there are runners, and then there are joggers, there are serious athletes that ride, and there are posers.
I like to think I'm a serious athlete when I ride - both mountain biking and road biking. A couple of hours riding in the woods up and down steeps, with assorted roots, rocks, turns, mud, and trees (that don't get out of your way!) - that's a real workout! Or riding 45-60 miles at an 18-19 MPH pace on a road-bike, that's a real workout too!
I've actually broken a mountain bike helmet when I took a spill and quickly found the ground - my head (helmet) hitting a rather large rock. Probably would have been badly concussed (or worse) if I'd dared to ride without. When you're going fast, and things go wrong - they go wrong quickly, and you don't have time to react.
So yeah, a helmet is actually a wise thing.
Indeed. Ran over a small paper bag on a downhill canyon road at around 50mph. Turned out the bag had a broken bottle in it (I suspect) so instant front tire blowout.
Sounds like you are not the “most people” that I was referring to. I just do my sissy girl, old lady cruising, in my semi-rural neighborhood.
You, OTOH, sound like a serious athlete, so a helmet is a wise choice for you.