Last weekend, I went to see The Father, Florian Zeller’s brilliant puzzle of a play, in which Kenneth Cranham plays a man who is suffering from dementia, and Claire Skinner his conflicted daughter – and it brought up all sorts of painful stuff. As the cast takes its curtain call, bleak thoughts of the future crowd in: your own, and that of all the people you love.

But it also reminded me of a couple of books, both of which I wouldn’t mind rereading now if I can only find the time. The first is Turn of Mind by Alice LaPlante, a debut novel that came out in 2011, was reviewed hardly at all, and then more or less disappeared when it should by rights have been a bestseller. Clever and gripping, it’s narrated by a retired hand surgeon, Jennifer White, whose closest friend, Amanda, has been murdered. Who killed Amanda? Jennifer had argued with her shortly before she died, and there is the awful fact that her body was missing four neatly severed fingers. But she is also suffering from Alzheimer’s disease. If she did have something to do with her friend’s death, she has no memory of it.

The second is Linda Grant’s 1998 memoir, Remind Me Who I Am, Again, in which she writes of her mother’s dementia and, seeking somehow to fill up the gaping space the illness leaves in its wake, retraces the history of her family. It’s a long time since I read this book, but its honesty and wit has never left me. At its heart is the simple cruel fact that most of us leave it too late to ask our parents the important questions. Who they are, and who we are: in the youthful rush to self-rule, we forget that without a working knowledge of the first of these stories, the second will likely always be opaque, only half-understood.