Old favourite songs famously have the power of recall: we listen after a long interval and the flavour of the past is with us again. The secret is not quite "in" the music for the music has acted like a sponge, absorbing (for example) all of what I was and what surrounded me as an adolescent in the 1980's . So now, in 2016, the song is capable of "re-releasing" it all and reawakening the dead. By contrast, returning to a once important book can seem like visiting a ghost town. Picking up Bertrand Russell's Autobiography, my marginalia are like the hieroglyphs of an extinct tribe. I can resurrect nothing of the original reading experience, the period feel, the excitement. It tells me: what you once were is lost.