If, like me, you’re a slow reader, you’ll know what it is to choose books carefully. How I’d love to be like my university friend who could speed-read a whole whodunnit in the bath, solving the mystery before the water was cold. But because of the snail-pace of my consumption, I often feel obliged to bypass thrillers and doorstop blockbusters. Life is short, after all. So I reach dutifully for literary fiction, relying, like P. G. Wodehouse’s Jeeves, on ‘some improving book’ to inform and entertain me.