I'm an EMS helicopter pilot (Emergency Medical Service). All summer long, nearly every night, we launch to go scrape up the broken skulls of the un-helmeted. I see it day in and day out. Helmeted riders do much better. Protect your egg-shell thin noggin. Please wear a helmet.
Your loved ones depend on you, and when I work the night shift, I don't want to have dispatch wake me up at 3 am with that rude tone over the radio for one of US!