Been saved by a helmet in every sport more than I've been bothered by one.

Just gently tap your forehead on the corner of a 4x4 post and then imagine doing that at 35mph.

Had my board hit me in the forehead when I was doing a kiteloop once and botched the landing. I saw stars but was fine after a minute... without a helmet I may been knocked out and drown.

There was an incident awhile back about a pro getting hit by his board in the head (and he wasn't using a leash). He died.

It's always your decision but my life is worth a little inconvenience. It's no worse than a seatbelt.

-tom