There is a particular quality of hospital light at midnight that I had not been in since my mother died in 2011 and had forgotten about entirely.

Her eyes opened and tracked and found me and she said: “Dad.

You’re back.”

And then, about nine seconds later, she said: “Dad.

You’re back.”

She said it four times in about twenty minutes.

Each time with the same slight surprise, each time as a new piece of information, and each time I said yes, and the fourth time I had to go out into the corridor.

That is what post-traumatic amnesia looks like from a chair.