Thanks for the detailed reply, Mark. I suppose I mean that I have never had anything that was diagnosed as a concussion, or that stopped me from living my normal life. I do recall days while I was in my early teens when I'd leave ski resorts with a headache after take a bunch of falls where I hit my head. But never anything that caused significant pain or stayed with me for more than a day. Nor have I ever lost consciousness.

I guess I pretty well agree with everything you've said, although struggle to accept it. I've always been someone who prided myself with risk assessment when I participate in activities, and decide which risks I'm willing to take. It's so hard to decide whether to take a risk to do something I love (e.g. biking) when I just don't have much of a perspective on how big the risk is. Sure, the worst case scenario is really bad, but the worse case scenario was always bad when I launched a 60 foot jump. I just wonder what the scenario looks like, where I have a bad, but not that unusual crash. Say one where I land with a hard impact on my body, but not my head. That's the kind of thing that's nearly guaranteed to happen eventually in a sport like mountain biking, but I have no idea how my body will respond.

I certainly will be investing in a great helmet for biking and definitely won't play contact hockey again. Ironically enough, after my crash I realized that after washing the padding of my helmet, I had put the pads back in backwards. Who knows if that could have contributed...

Regarding the Ami, I am planning to start a gradual wean off of it. I do wish I knew this before, as I didn't ever even try 10mg. The doctor just prescribed me 50mg off the bat, when my symptoms weren't even that painful.