shadowcycling through the trees

...beautiful bike ride early this morning.  Blue sky, bright low sun and very cold.  Strange thing happened.  I stopped by the side of the road and stood astride my bike to get my camera out of my back pocket.  A car went passed me in the other direction.  A few seconds later I could hear someone behind me shouting 'are you alright?!'  I looked round and 20 or so metres down the road was the car that had just passed me and the driver was running towards me.  I told her I was alright and thanked her very much for her concern.  Puzzled, I set off again.  About a mile down the road I stopped to take a photograph.  Another cyclist rode past me asking if I was alright.  Very puzzling - I'm wondering now maybe old age is just making me look as if I've had an accident all the time.