In The Great Gatsby, what is the stylistic meaning of the phrase: "he had lost that part of it, the freshest"?
This passage comes when Gatsby is telling Nick about his love for Daisy, and how he never was able to recapture the first glorious feelings of love he had for her after her marriage to Tom:
He stretched out his hand desperately as if to snatch only a wisp of air, to save a fragment of the spot that she had made lovely for him. But it was all going by too fast now for his blurred eyes and he knew that he had lost that part of it, the freshest and the best, forever.
(Fitzgerald, The Great Gatsby, ebooks.adelaide.edu)
Returning from France, Gatsby visits Louisville, where he had courted Daisy and fallen in love, but the place seems empty and barren without her presence. Knowing that she is married and therefore seemingly out of his reach, the visit is more of a desperate attempt to relive his feelings. When he leaves the city by train, he "stretches out his hand" in a metaphorically physical grab for happiness, but he knows that the innocence in their early relationship is gone forever.
This passage, narrated in the third-person by Nick, shows some of the poetic pain that Nick feels in sympathy with Gatsby, and idealizes Gatsby and Daisy's love while acknowledging that events have moved on, leaving Gatsby behind.
This quote expresses Gatsby's wistfulness and nostalgia for an experience that only seems able to endure a moment or two. The adjective "fresh" has positive connotations: something fresh is fragrant, healthy, and best enjoyed immediately. Freshness is a quality that cannot last long, like the innocent and pure, early love between Daisy and Gatsby.
Daisy has married another man, and Gatsby has lost her, but the memory of their early connection lingers. As he reminisces about those days to Nick, he longs for the newness of the early days, when their love had the most potential. This is what Gatsby means when he uses the superlatives "the freshest and best" to describe the hope he experienced during his earliest days with Daisy.