I got my first scooter in 1960 when I was a very young, dumbass, "invincible" kid. My folks did not protest or give me any grief. Looking back now I wonder if they did not understand the risk or did and just didn't care about me, just kidding, lol. Back then helmets were things the football players wore. Never even though about wearing one. I was also self taught and learned how to ride through the school of hard knocks.
Again, I am NOT pro government and am very conservative. But I will say that without some "liberal" big-brother intervention I would probably not have become educated (some may call it brain washed) about the risks and consequences.
And that is my point. Make sure you fully understand the risks you are taking and how a helmet can mitigate those. Terry spoke about hitting your head just falling down. That is sufficient to kill you, no kidding, that's all it takes if you were to hit your head on hard surface. See the updated Hurt interview. Most motorcycle crashes result in a fall of only 5 or 6 feet. Sure some folks may fly over cars, etc., but if you low side you only "fall" a few feet and speed is not really that much of a factor unless it is really excessive. Even a spill like this can cause serious or even fatal brain injury.
Your choice, just know the facts and accept the risk if you want.