I've seen too many people dieing on a bike without an helmet, even close friends.. Here in italy is no joke, theres not a lot of police to check if you do have an helmet, and everybody drives like an animal,cagers and bikers... It's just a couple of years that we have a strict speed check only on the highway, but before you could actually do almost whatever you wanted, and going down on a bike is really really easy, with tight roads and curves... If there is even a 1% chance of saving your life wearing an helmet, that's the right thing to do....
Bottom line, I never drive without an helmet....