Helmets aren't going to save you from brain damage above a certain speed. Something like 15 MPH. What they DO save you from are nasty cuts and scrapes on your head/face.
I grew up wearing one, but only do so now for branches in the trees. I kinda feel naked without it. I also hate wet goggles. I find your gogs get more wet when you lift them up on a beanie when its snowing.