Anyone writing about smell and memory, it seems, is obliged to start by taking tea with Marcel Proust. Every treatise on the psychology of smell contains a reference to a scene from A la recherche du temps perdu. The depiction is often at the umpteenth hand, three lines long at most and whittled away until almost unrecognizable: the narrator drinks a cup of tea, dunks a piece of cake in it and suddenly the smell takes him back to his youth in Combray. In the original version by Proust, the scene covers a good four pages. His is a subtle, introspective account of the trouble it costs him to come to grips with his feelings. One cold winter's day he comes home feeling depressed. His mother offers him a cup of tea, and one of the small fancy sponge cakes called ‘petites madeleines’.

The narrator tries to discover where the sudden delight had come from, but fails in his attempt.