There was an irony and a paradox here: Franco thought of Pontito constantly, saw it in fantasy, depicted it, as infinitely desirable – and yet he had a profound reluctance to return. But it is precisely such a paradox that lies at the heart of nostalgia – for nostalgia is about a fantasy that never takes place, one that maintains itself by not being fulfilled. And yet such fantasies are not just idle daydreams or fancies; they press toward some fulfillment, but an indirect one - the fulfillment of art. These, at least, are the terms that D. Geahchan, the French psychoanalyst, has used. With reference in particular to the greatest of nostalgies, Proust, the psychoanalyst David Werman speaks of an 'aesthetic crystallization of nostalgia' - nostalgia raised to the level of art and myth.
Oliver Sacks, An Anthropologist on Mars: Seven Paradoxical Tales
nostalgia