Your brain can't heal itself when you hurt it.
i work at a brain injury rehab. Wear your helmet. Most of our clients will never return to their jobs, families, relationships, many are incontinent and some will never again have the simple pleasure of drinking a glass of cold water when they are thirsty, due to swallowing problems. Wear your helmet. Our "high" achievers have part time jobs wiping tables at fast food restaurants - with a job coach beside them all the time - whose name they can never remember. Wear your helmet.

A lot of their injuries come from car crashes, true, but some are from astonishingly small hits - a fall while hanging off a basketball rim, or slipping on an icy parking lot. Wear your helmet. The cranium is only designed to protect your brain at human running speed - maybe 8 mph. And your wonderful, wonderful brain does not know how to mend itself. Wear your helmet!