Sure, I'll tell it again..... I think about it everyday....
Back when I was 12, my best friend and I both rode our dirtbikes pretty much anytime we could. We were out at Greg's parents cabin at the lake, waterskiing, but we both had our bikes with us. The beach was a few hundred yards down a trail from the cabin. Greg had an RM-100 that he just got, and he gave his old XR-75 to his little brother.
About lunchtime he wanted to go to the cabin and get something we forgot, so he jumped on that little XR and putted up to go get it. He left his helmet on the beach with us. He was gone for a long time. After about 30-40 minutes, I fired up my YZ to go see what he was doing for so long.
As you got to the cabin, the trail came out of the bush and turned onto the driveway. Just before this junction, the trail had a tight turn followed by a little climb up out of the ditch next to the driveway. You kinda planted your right foot, made the pivot and popped up onto the road.
I found Greg laying on his rightside in the middle of the little turn, still half sitting on the bike, also laying on it's side. He was dead, having smacked his head on the only rock bigger than an orange for miles. I didn't know that at the time, all I knew was he was seriously hurt(I hoped) or dead(I thought) and I was freaked. So I had to ride back to the lake and tell his folks this. You don't ever want to have to do this, believe me.
They didn't really like me much anyways, I had gotten Greg into riding in the first place and they didn't like that. After all Hell broke loose and the paramedics were called and the whole, awful truth was out, I had to ride home 2 hours with Greg's Dad and little brother. The worst ride of my life, by far.
Greg was a good rider, but not as fast as me, so he would always push it when we rode together. He had alot of trouble with his right knee getting wrenched trying to keep up with me, so it was always weak. So I am pretty sure what happened was... Greg went off on his old minibike without a second thought about crashing, the trail was 1st gear all the way, and hey... we were on 'fast motocrossers', this was his old minibike. When he got to the end, he planted his right foot and wrenched his knee, the one that is sore and tender to start with. So he goes down, probably half on purpose, to roll around and hold his knee and scream and cry, like you would do when you are that age. Only he never got to that part, he crushed the side of his head in and never moved again after hitting the ground. I am very sure if he was wearing his helmet, the worst he would have had was another sore knee.
Another time, I was 15 and at a different lake with my parents, my sister and her boyfriend. Dad had some quads and trikes that they used to ride the trails out there with. Sis's boyfreind wanted to go out on Dad's 83 Quadrunner, one of the worst designs ever produced.... way to much wieght on the rear, could stear the thing and it was dangerous on hills. The folks said go ahead, but you have to wear a helmet.
I had just bought a new Bell MotoIII and was pretty pleased with the whole affair, that lid was like Star Wars back then. Sis's B/F can't find a helmet to fit right in Dad's stash, so I very reluctantly let him use my new Bell.
They came back a few hours later. Dad's quad was a pretzel and my lid was cracked wide open. His ribs were very sore, but his melon was fine. He was climbing a steep hill, powered out in second, and just dumped it into first(love those auto trannys) and it reared up and over. On top of him. The front rack is what crushed my helmet, the bars are what hurt his chest according to Sis.
I was mildly happy he was alright, but I was extremely pissedoff about my helmet. I made him buy me a replacement.
All anecdotal garbage, I know...... but it sure made an impression on me. Especially combined with all the times I've crashed myself. You don't race off-road with any seriousness without crashing.... alot. Head first into jump faces, skidding for what seems like miles across gravel pits with a bike riding you, getting knocked down mid-pack in the first turn and run over by 15 bikes...... Never once did I regret wearing a helmet in such a situation. My couple of street crashes never whacked my head as hard as many dirt crashes I had, but I did grind one down a fair ways sliding down the street once. Again, anytime I've crashed on pavement, I've been dam glad I had my lid on. Thankfully, I haven't gone down on a raodbike more than a couple or 3 times.....
Does this mean helmets will save your life in any and every case? I don't know. I do know..... I never ride any bike more than 6 inches without putting mine on.