You can get a full-covered motorcycle helmet if you want ultimate protection

The modern helmets are designed for light weight and "aero dynamic" reasons. Sometimes I think if the aero dynamic doesn't matter I must as well just get a skateboarding helmet.

I think one has to be smart when an accident occurs, to be able to put yourself in such position that will reduce damage to your vital parts, like your head. Maybe you can watch more motorcycle racing and observe how the riders react when they are thrown out of their bikes.

I have never had any major accident relating to cycling. I think I am still too conservative in terms of riding, though I am sometimes too fast for people( not experienced) to catch.