As an avid cyclist I am convinced bike helmets work. Yea they mess the hair, maybe aren't the right colour or design, but for me striking the pavement or a tree with my head is not an option. That would definitely mess the hair, the colour would be red and the design, deformed.
Although I ride thousands of kilometers every year I have only been in a few crashes. But I never know when the next one will occur. Most, ironically, have been off the road and sometimes with nobody else around. The conditions were just right for that crash. Something I did not anticipate, it just happened. So why is it that people believe that since they are not on a road or there is very little traffic they won't crash? It can happen, anytime, anyplace at pretty much any speed. So why take a chance?
I hope adults take heed. All my crashes, where the helmet was replaced rather than my head have taken place in my adult life. Maybe you are a better rider, I don't know, but please lead by example. There are little eyes watching you!