A cyclist wears a helmet and rides their bike on the right side of the road where I can easily see them flowing with the traffic if they’re going the same way I am. If they’re going in the other direction, they’re on the left side and I can also see them coming much easier.
An idiot doesn’t wear a helmet and rides on the wrong side of the road… and on a sidewalk. This way I’m more likely to run you over if I’m turning left off a busy street. And, well, I guess I understand why you’re not wearing a helmet – nothing of value to protect.