Invincible?

After yesterday's near death experience I carried on to work and convinced myself I was fine, I worked a busy day without thinking about it too much and it was not until I finished work that I started to get a bad head, feeling quite achy and tired.  Although I wasn't badly injured I suppose getting hit by a car was always going to shake me up a bit whether I thought I was fine or not.
Cycling to work early in the morning I was going straight on at a mini roundabout, I could see a car coming quite fast from my left but being as I'd already entered the roundabout I assumed it would of course slow down or stop.  Unfortunately this was not the case and the back end of my bike got clattered with me helpless to avoid the crash, I skidded and careered about 10 metres down the road somehow inexplicably managing to jump off my pedals and land on my feet.  I stood in the middle of the road shouting with my hands in the air and the fella abandoned his car in the middle of the roundabout and ran over to me to see if I was okay, "I don't know, I think so" I said, and not knowing what else to do started trying to repair my bike.  The man admitted he wasn't concentrating and was apologising profusely and so I ended up trying to calm him down when I saw he was trembling and almost crying.  Even though I'd almost gone under his wheels I felt sorry for him and assured him that apart from cutting my leg I was fine and he need not worry, I shook his hand, got my bike sorted, blocked it out of my mind and became more concerned about getting to work on time.
I was busy all day I didn't really reflect on it too much until I got home and although I thought I was fine I must have had a bit of delayed shock as I suddenly had a bad headache, a stiff neck, felt achy all over and couldn't stop myself crashing out to sleep for a few hours.
I feel fine now, and I'm not bothered by it, I'm more concerned about the mental state of the poor fella who hit me. There is one thing that I've realised, that there's a fine line between how invincible I think I am and how reality could prove me wrong in a split second.