The Great Gatsby Ch.6
He talked a lot about the past, and I gathered that he wanted to recover something, some idea of himself perhaps, that had gone into loving Daisy. His life had been confused and disordered since then, but if he could return to a certain starting place and go over it all slowly, he could find out what that thing was...
Gatsby realizes that something in the past went wrong with Daisy, but instead of trying to solve it now, he wants to just change the past, moved by his exaggerate self-esteem, not realizing that is not how things work.
"I wouldn't ask too much of her," I ventured. "You can't repeat the past." "Can't repeat the past?" he cried incredulously. "Why of course you can!" He looked around him wildly, as if the past were lurking here in the shadow of his house, just out of reach of his hand.
Gatsby's confidence makes him almost ridiculous in this famous quote; he gets to the point of being hysterical when he realizes that something has to be out of his reach, no matter his wealth or power, and there is nothing he can do about it.
He wanted nothing less of Daisy than that she should go to Tom and say: "I never loved you." After she had obliterated four years with that sentence they could decide upon the more practical measures to be taken. One of them was that, after she was free, they were to go back to Louisville and be married from her house—just as if it were five years ago.
In his desire of reverting things to the past, he includes the desire for Daisy to get back to what she was, not only forgetting but even denying everything that happen in the last 5 years.
But the rest offended her--and unarguably, because it wasn't a gesture but an emotion. She was appalled by West Egg, this unprecedented "place" that Broadway had begotten upon a Long Island fishing village--appalled by its raw vigor that chafed under the old euphemisms and by the too obtrusive fate that herded its inhabitants along a short cut from nothing to nothing. She saw something awful in the very simplicity she failed to understand.
In this quote, Daisy's view is expressed: Even if she somewhat likes Gatsby, she is still a member of East Egg, and because of this, she is suspicious and snobbish towards everything that is "new rich". This is the main reason she does not like the party and also the main cause of the impossibility of a marriage with Gatsby.
Through all he said, even through his appalling sentimentality, I was reminded of something--an elusive rhythm, a fragment of lost words, that I had heard somewhere a long time ago. For a moment a phrase tried to take shape in my mouth and my lips parted like a dumb man's, as though there was more struggling upon them than a wisp of startled air. But they made no sound and what I had almost remembered was incommunicable forever.
Nick almost finds himself sympathizing with Gatsby for an old memory that comes up to his mind, but he decides not to do it, maybe because, in a snobbish way, he considered it way more tragic than Gatsby's "appalling sentimentality".
The truth was that Jay Gatsby, of West Egg, Long Island, sprang from his Platonic conception of himself. He was a son of God--a phrase which, if it means anything, means just that--and he must be about His Father's Business, the service of a vast, vulgar and meretricious beauty.
This quote summarizes the view that Jay Gatsby had of himself, God-like and infallible; platonic refers to the fact that this image is a mere idea in his mind and does not coincide with the real world.