I have been on helmets since they were first invented. I was not only a semi-pro motorcycle racer but because the safety director for the American Federation of Motorcyclists. The way a track motorcyclists falls is completely different than the way in which a bicyclist typically falls. That is why a hard shell seems to help motorcyclists more though it really does not in collisions of the head with any object.
I just want this CLEAR AS A BELL - helmets ONLY help when you are in a minor crash and they only protect your head from road or gravel rash and nothing more. So be careful out there and never believe for one second anyone that claims that their live's were saved by a helmet because that is not possible given the required density of the foam because of the limited size of a helmet.
Wear a helmet, and I do, but do not take any chances in which you might believe you're protected from stupid acts by your helmet.