I don't want to be hyperbolic, but not wearing a helmet when you ride a mototcycle is literally the dumbest thing in the world. It is SO SO SO SO SO stupid. It's already incredibly dangerous to ride a motorcycle--a crash results in injury or death to the motorcyclist more than 80 percent of the time. Many un-be-helmeted motorcyclists aren't impressed with the stat that helmets "***ONLY***(?!?!?!?)" reduce incidence of death 37 percent (or, bafflingly, they believe that helmets actually increase the likelihood of injuries). Personally, I find this statistic very impressive, but then, my role in a motorcycle gang would probably be, like, t-shirt maker. Or treasurer.  So! Even if you enjoy expressing your badassery/stupidity through not wearing a helmet because a 1/3 increase in likelihood of survival isn't doing anything for you, consider the fact that helmets also reduce the likelihood of brain injury by nearly 70 percent. Even if for some reason you think that death is cool, I feel like we are all unified in the fact that being paralyzed or brain-dead is not an aspirational state.  Now, I'm pretty sure that if you're anti-motorcycle helmets, you are probably not reading this. But if you are someone's mother or a spouse threatening divorce over your partner being the biggest of fools (Hi! Thanks for reading!), perhaps I can interest you in this fantastic guide to motorcycle helmets on the Lanesplitter blog at Jalopnik, "Everything You Ever Wanted to Know About Motorcycle Helmets." The post covers everything from whether you need to spend a lot on a helmet (you don't) to whether helmets really inhibit peripheral vision (they don't) to how to clean your visor (you should do this).   Happy reading, and good luck convincing the dumbass in your life to not let his or her brain get squashed! After all, only 19 states (and the District of Columbia) have helmet laws, so for the most part, they're free to make their own choice.