Over a few rainy days last week I found myself reading Samuel Butler’s The Way of All Flesh.

When I read the description on page 9 of penny loaves being distributed by the bereaved to the village on the day of a funeral I said wisely to my anthropologically knowledgeable self that yes I had come across this custom somewhere before. Then reading on page 16 of how George Pontifex had recast in modern idiom the advertising blurb for a religious book I wondered quite how that had the ring of familiarity. On reaching page 35 where Mr Allaby advises his five unmarried daughters that they should play at cards to decide which one of them should throw her cap at Theobald I had a strong suspicion that I must have read the book before.

For the life of me although I greeted each scene with warm familiarity as it appeared, I could not foretell what was going to happen, apart from having a vague presentiment that a prayer meeting would play a role. The prayer meeting duly took place on page 180 so there was no longer any room for doubt. I had read the book before.

This set me wondering what might be the minimum number of books that in the present state of my memory would provide me with an endlessly fresh reading experience if I were to read them repeatedly one after another. And further, at what point in time will my memory function be so reduced that one book will do?