I guess it's different in Chicago, but among my friends the people who get scolded, chastised, and made fun of are the few who don't wear helmets. Most of my friends -- who, if you saw them you'd immediately judge as too-cool-for-school hipsters even though they are genuinely nice, creative, and awesome people -- wear them.

I wear mine about 90+% of the time, but there is the occasion when I'm going only a short distance on slow residential streets or paths, or other rare circumstances, when I don't. I actually hate that I get scolded like a little kid about it, because I am an adult who can make decisions to do things that are risky and it's my own damn business if I do. I mean hell, now I hear that helmets are required gear for downhill skiing and snowboarding and I sure as hell didn't wear a helmet for the 20 years of my life that those were regular activities.