It has long been a theory of mine that, like film classifications, books could carry a kind of age-appropriate rating. This wouldn’t be to classify books as potentially damaging to the sensibilities, but rather to stipulate the age needed to obtain optimum sensibility for appreciating the wisdom of the book.

I have long thought it absurd, for example, to expect teenage schoolboys to appreciate the subtlety of Jane Austen. The nuances of ladies being wooed with nice manners and houses are lost on minds for whom ladies being wooed has only Carry On film connotations. While Alain Fournier’s Le Grand Meaulnes played glissandi on my 17-year-old heartstrings during A-level French lessons, had I discovered the book first in my 40s, the idea that one’s adolescence was somehow the peak of emotional experience, and a lost domain to be forever rediscovered, would have left me bewildered.