Do I wear a helmet? Ugh. I do when I'm riding through a precarious part of town, meaning Midtown traffic. But when I'm riding on secure protected lanes or on the paths that run along the Hudson or through Central Park - no, I don't wear the dreaded helmet then.
I ride my bike almost every day here in New York. It's getting safer to do so, but I do have to be fairly alert when riding on the streets as opposed to riding on the Hudson River bike path or similar protected lanes.
You can know or not know how a car runs and still enjoy riding in a car.