I read all the posts, didn't see much mention about the type of riding.
For English riding of any kind, which I believe the OP does, I can see where a helmet should be considered standard equipment. Nothing to hold onto when the horse is acting up.
I can see some sense in wearing a helmet for competitive western riding, such as broncs, bulldogging, barrels, poles, etc.
For trail riding (this is the trail riding forum, right?) in a western saddle, I'm more concerned about rain down my neck and skin cancer on my neck, face, and ears, than getting my head cracked. In 45 years of handling horses I've gone down a number of times and only got a concussion once. In that instance a horse fell on a road with me and I landed smack on my face. Broke my nose and got a bit of road rash on my cheek. Helmet wouldn't have done a thing.
For western trail riding, I consider good leather western boots, with a riding heel, to be of greater importance than a helmet. Try getting one of these new lace-up, lug-sole, tennis shoe-type "riding shoes" out of a stirrup in a hurry!
But that's just me. I only make the rules for myself.
Thought I'd post those thoughts, because in my mind different styles of riding require different safety equipment.
Last edited by thenrie; 02-17-2013 at 11:13 PM.