I admit it, I was deep in a day dream. I was thinking about my pension. I was (to be frank) thinking about my boss's pension too, and some questions I'd like to ask him. Then suddenly, whack! I had that slow motion thing. But unlike the cockroaches you see in slow-mo on nature films, where they find a foot coming towards them laughably slow and can take evasive action, I was unable to do anything except fall kind of through my bike, hitting knee, elbow, thigh. And giving each a good hit and scrape.
The cause? I think I had hit a ridge with my tyre and because it was wet, slipped and fell.
The ridge was simply the join between two bits of tarmac - one green, one grey - with a little metal ridge to seperate them. I find that moving at an angle between two heights on a surface is very dangerous somehow, and slippy.
Anyway, karmacycle escapes with minor injuries and a few aches - luckily it was in a quiet spot by the canal so no-one was there to run me over.
Try not to think about pensions while you're cycling.