I'm 55 YY. I have been riding for many years. My business is bicycles. I have never had an on road accident that involved a vehicle. I have had a few racing involved mishaps that resulted in roadrash but no head related stuff. I have had plenty of MTB hmmm "controlled crashes" or "downhill headers" and "endos" I have been using a helmet since.....77'. However, again, I have never actually had a car hit me or hit one. I am so used to riding with a helmet that I feel neked with out it.