It does work both ways though, EDDIE51.
Having recently returned to cycling after some years, I'm shocked at the actions of some motorists. It's fairly regular that I get cut up by a motorist who can't wait until you get past a junction before they turn left. Then there's the motorists who can't wait for a gap in the traffic before passing you if it's a slightly narrower road and come within an few inches of your handlebars. All for saving a few seconds off their journey time.
Having said that, there's probably an equal number of stupid cyclists. We've all seen the ones who don't think traffic lights apply to cyclists and who cycle on pavements etc etc.
As to helmets, yes I do wear one but I'm not sure how effective they would be in a collision with a motor vehicle. I can see them saving you getting a bump on the head or some scratches if you simply fall off, but in a collision with a fast moving motor vehicle I'm not sure they'd offer much protection. Better than nothing though, I suppose.