I think the whole question of helmet encouragement and requirement stems from the perceived responsibility of government and society to safeguard the health and safety of its citizens but is also for its own convenience. Such laws or policies often are enacted to protect those who have to pay for the injuries of individuals who are injured and subsequently require public care. This is the way of the world, but in the process, the rights and responsibilities of the individual get lost or are at least minimized.
I haven't worn a bicycle helmet in decades. They are expensive, uncomfortable, a hassle to carry around, hardly stylish, etc. and they have only once prevented a head injury for me, and of course I am glad I was wearing one at the time. But in my many years of riding (I turned 60 last November), I have developed my own personal safety strategy the far outweighs the focus on if and when I might be injured. This includes riding on back streets, extreme shoulder areas, and even sidewalks with due respect for pedestrians. I avoid major roadways without bike lanes especially during peak hours, I avoid major intersections and especially queuing up in a turn lane far from the curb preferring crosswalks until I can get back to a curbside route.
I also ride a low cruiser style bike so I'm not high and tilting forward ready to fall. I did have a major accident of this sort with my old mountain bike (I am 6 feet plus and the bike was a high frame) where I hit a traffic circle in the dark (without a light - my bad) at moderate to high speed and I sailed all the way over it flipping all the way over onto my shoulder and back. My head never once hit the pavement although I spent 4 days in the hosipital nursing broken ribs and a totally separated shoulder.
Bottom line: I take full responsibility for my personal safety and the consequences of my bicycle riding. I only ask that no one bother me with chides about not wearing a helmet (people do this) or legal requirements that I have to wear one (I hope this does not happen.) In my motorcycling days I rarely wore a helmet out on the road (unless it was raining) but usually in the city. Second bottom line: it was my choice to wear one or not.