I don't really understand why this debate still goes on. I mean, I understand why some people are against the compulsory wearing of helmets, but I just don't get why you wouldn't. A few years ago, whilst riding back from the LBS, I got hit-and-run(ed) whilst I was the right of way at a roundabout; slightly wet road, clear viz, about 1100hrs in the morning. I crossed the roundabout with all the rights in the world. Right up until some woman pulled out, sent me across the back of her car, *****d off down the road and left me in the middle of the road where a mercedes E-class nearly finished me off. I ejected over the bars (inverted) and landed on the back of my head on the kerb stone. There was literally not a lot of helmet left (cheers to Giro for the crash replacement...), but I was all but in-tact. The police wanted photos of it etc, due to the damage sustained, but ultimately, nothing further was done. I would literally not be here if I'd not been wearing the lid and have not and will not ever set out on my bike without one again.
We've all got stories of crashes, usually caused by running out of talent if we're honest, but I have a slightly different take on it too. Whilst out riding with the wife (a doctor..) and a bunch of mates at Coed-y-Brenin some years ago, we stopped for a breather, away from the marked trail (but near a short-cut) as some lone rider, without a lid came by. As I said, we weren't on the actual trail or blocking his route. We said 'hi' and exchanged the usual MBer pleasantries (mum always said manners cost nothing...). Waiting for a return of the salutations, we instead got a load of abuse hurled at us as we were apparently blocking the trail. This guy was clearly going at it, presumably getting his fix of exercise etc etc (not really interested), but riding a trail centre, alone, in the p*ssing rain, without a lid? That's down-right irresponsible and selfish, because all of a sudden, your crash hasn't just ruined your day; it's ruined mine when I have to scrape you up off the floor, my wife has to deal with your cranial bleed and the forestry commission have to stretcher you off the hill. I'm fairly 'live and let live', but this really is one thing that ticks me off.