This is why...

... I suddenly found myself going from vertical to horizontal in a split second this morning.

In the background you can see the main road - not shiny at all. In the foreground there is a parallel relief road (serving the houses) & the pavement. They are both shiny. The shine is not water, well not *wet* water, but a thin coating of ice from the rain that fell last night & froze on contact with the ground.

The back of my head has a new lump on it this evening.