4 ideas
As an adult, the narrator dips a small madeleine cake into lime-blossom tea and is flooded with an unexplained joy. After straining to trace it, he recognizes the taste as the one his aunt Léonie gave him on Sunday mornings in Combray. From that single taste the whole town, its streets, church and people rise up intact, when years of deliberate recollection had returned only the scene of his bedtime drama.
Voluntary memory, the deliberate effort to recall, gives back only dry, schematic facts stripped of the feeling of the moment. Involuntary memory is set off by chance when a present sensation matches one stored in the past. It returns the past whole and alive, because the sensation was never processed by the intellect and so was never worn down by it.
Love in the novel, above all Swann's for Odette and Marcel's for Albertine, is fed by jealousy, doubt and the other person's unavailability rather than by who that person actually is. Once the beloved is possessed or certain, desire collapses into boredom. Only the threat of loss revives it, so the lover suffers most for someone he does not even find compelling.
Time destroys people, social worlds and even the self, as the narrator sees when he meets his aged acquaintances at the final Guermantes reception. Truths found through involuntary memory stand outside time. Only a work of art that fixes them can redeem a life, so a life that seemed wasted in salons and failed love turns out to be the raw material of a vocation.