It never ceases to amaze me that this topic is still even discussed.
My friends dad fell on his bicycle without a helmet and is now a vegetable. What more do you need to know???
This man will never know his grandchildren, no longer knows his own wife or children, and basically has no quality of life.
Maybe I'll go to the hospital and visit the rider in my neighborhood who got into an accident a week ago. He couldn't stop in time when a van short stopped in front of him and he went right through the back window head first (with a helmet).
Just put on a damn helmet.