As a kid, we never wore helmets. I know of nobody ever receiving a head injury by falling off their bikes. I had plenty of road rash from over-exuberance, but never a head injury. Or maybe I just don’t remember it due to a head injury...never mind. It is a good time in American history to be old.
An associate of mine lost his son in a biking accident.
Usually wore his helmet but one day he was just going down the street so he didn’t wear it. Car clipped him and he hit his head on the curb.