The best explanation of Proust I have ever encountered is in a small book by Edmund White titled Marcel Proust, from which I have taken the following extract.
This idea, that life presents us with but one book to write, the story of our own existence which we must merely translate, was one to which Proust would remain faithful....This utterly democratic view that we are all novelists who have been handed by destiny one big book, the story of our lives, appeals to anyone who has ever felt the tug towards self-expression but has feared not being skilled enough to get his feelings down. - Edmund White, Marcel Proust
Swann's Way, of course, is only the first volume of his masterpiece titled, in English, Remembrance of Things Past. The whole work is a long memoir dealing extensively with the enjoyment of beauty and with the pleasures and pains of love, in one form or another; but Proust wanted to make it dramatic. He did this by inventing a fictitious authorial motivation, which was that he was making an unprecedented attempt to recapture the past "in all its most ephemeral details," almost as if he were a time traveler. He pretends that he has the unique ability to do this, and uses the anecdote about the petite madeleine as an illustration. Supposedly he dipped one of these delicate fluted cakes in a cup of tea and the taste brought back uncannily vivid memories of his experiences as a boy in the little town of Combray.
The desire to recapture his entire past and the difficulties involved in trying to do so are the main theme and the main dramatic conflict of the entire work. The last volume of Remembrance of Things Past is titled The Past Recaptured, and there illusion is created that the quest for lost time which Proust began in Swann’s Way has been successful.