Talking of Proust, most people know he's famous for the passage about eating madeleines. It's in the first book, quite early, actually. (My husband told me that a lot of people only read that one. Gee, I wonder why?)
But anyway, here it is (because Proust is quite verbose, I cut a few paragraphs from the middle and half-a-page from the end):
Many years had elapsed during which nothing of Combray, except what lay in the theatre and the drama of my going to bed there, had any existence for me, when one day in winter, on my return home, my mother, seeing that I was cold, offered me some tea, a thing I did not ordinarily take. I declined at first, and then, for no particular reason, changed my mind. She sent for one of those squat, plump little cakes called "petites madeleines," which look as though they had been moulded in the fluted valve of a scallop shell. And soon, mechanically, dispirited after a dreary day with the prospect of a depressing morrow, I raised to my lips a spoonful of the tea in which I had soaked a morsel of the cake. No sooner had the warm liquid mixed with the crumbs touched my pal than a shiver ran through me and I stopped, intent upon the extraordinary thing that was happening to me. An exquisite pleasure had invaded my senses, something isolated, detached, with no suggestion of its origin. And at once the vicissitudes of life had become indifferent to me, its disasters innocuous, its brevity illusory--this new sensation having had the effect, which love has, of filling me with a precious essence ; or rather this essence was not in me, it was me. I had ceased no w to feel mediocre, contingent, mortal. Whence could it have come to me, this all-powerful joy? I sensed that it was connected with the taste of the tea and the cake, but that it infinitely transcended those savours, could not, indeed, be of the same nature. Where did it come from? What did it mean? How could I seize and apprehend it?
I drink another mouthful, in which I find nothing more than in the first, then a third, which gives me rather less than the second. It is time to stop; the potion is losing its virtue. It is plain that the truth I'm seeking lies not in the cup but in myself. The drink has called it into being, but does not know it, and can only repeat indefinitely, with a progressive diminution of strength, the same message which I cannot interpret, though I hope at least to be able to call it forth again and to find it there presently, intact and at my disposal, for my final enlightenment. I put down the cup and examine my own mind. It alone can discover the truth. But how? What an abyss of uncertainty, whenever the mind feels overtaken by itself; when it, the seeker, is at the same time the dark region through which it must go seeking and where all its equipment will avail it nothing. Seek? More than that: create. It is face to face with something which does not yet exist, which it alone can make actual, which it alone can bring to the light of day.
. . .
And suddenly the memory revealed itself. The taste was that of the little piece of madeleine which on Sunday mornings at Combray (because on those mornings I did not go out before mass), when I went to say good morning to her in her bedroom, my aunt Léonie used to give me, dipping it first in her cup of tea or tisane. The sight of the little madeleine had recalled nothing to my mind before I had tasted it; perhaps because I had so often seen such things in the meantime, without tasting them, on the trays of the pastry cooks' windows, that their image had dissociated itself from those Combray days to take its place among others more recent; perhaps because, of those memories long abandoned and put out of mind, nothing new survived, everything was scattered; the shapes of things, including that little scallop-shell of pastry, so richly sensual under its severe, religious folds, were either obliterated or had been so long dormant to have lost the power of expansion which would have allowed them to resume their place in my consciousness. But when from a long-distant past nothing subsists, after the people are dead, after the things are broken and scattered, taste and smell alone, more fragile but more enduring, more immaterial, more persistent, more faithful, remain poised a long time, like souls, remembering, waiting, hoping, amid the ruins of all the rest; and bear unflinchingly, in the tiny and almost impalpable drop of their essence, the vast structure of recollection.
From Swann's Way by Marcel Proust