In the middle of the night, I woke up (if you can call being semi-conscious being awake), walked purposefully towards the door to go to the bathroom — and almost knocked myself out.

The reason was that in the twin states of entire darkness and semi-somnambulance I was facing in a different direction from the one I thought I was facing. As a result, instead of walking through the door, I tried to walk through the wall.

The next few days brought nausea and headaches. After much prevarication I went to Accident and Emergency, where I waited petrified among people for whom “social distancing” means not quite touching you, and who wore their masks as a chin-warmer.

An hour and a half later I emerged into the twilight, secure in the knowledge that I had nothing more serious than mild concussion. I failed to do much writing, but I was pleased to have read a further 17% of my book.