The figure of Jay Gatsby fascinates Nick Carraway because he incorporates the quintessential American ideals of endless progress and self-creation (see quote 1 in the third link below). Gasby tries to find American dreams and promises in his lived experience. According to Nick's story, Gatsby embodies the founding myth of American culture, that of the new and fresh beginning. At one point of his narrative Nick says that Gatsby "invented just the sort of Jay Gatsby a seventeen-year-old boy would be likely to invent". At the end of the novel, Nick goes back to Gatsby's empty place and has a vision of another age when "the old island . . . flowered once for Dutch sailors' eyes - a fresh, green breast of the new world" and all dreams seemed possible (see quote 9 in the thirk link below). Nick thus links Gatsby to this quest for dreams.
Nick Carraway first encounters Jay Gatsby at the end of Chapter One of Fitzgerald's The Great Gatsby, but only for an illusionary moment. Gatsby stands with his arms outstretched, trembling and gazing at the green light at the end of Daisy's pier, and then he is gone. Gatsby is an enigmatic man who longs to recreate his romanticized past because he has no future, only the present.
Gatsby has a mystique about him because very little is known of him; only distant impressions are suggested. Just as he suddenly appears on a lawn in West Egg, Jay Gatsby spontaneously has parties with strangers who know nothing of each other as well as nothing of Gatsby. In Chapter Four, he asks Nick, "What is your opinion of me?" and states that he is going to tell Nick about himself so that there is no "wrong opinion" of him. But, it is not until Chapter Six and Seven, the reader does not learn of Gatsby's background or of his criminal activity. Until this point, Nick and the reader only are told that Gatsby had parents from the Midwest, but when Nick asks specifically, Gatsby says, "San Francisco." He claims to have gone to Oxford, but only produces a photograph that was supposedly taken while he was in college, and chokes on the words. Nick narrates,
He hurried the phrase" educated at Oxford," or swallowed it, or choked on it as though it had bothered him before. And with this doubt, his whole statement felll to pieces, and I wondered if there weren't something a little sinister abou him, after all....For a moment I suspected that he was pulling my leg, but a glance at him convinced me otherwise.
Something in Gatsby--"the great Gatsby"--hints at magic and illusion as in "the Great Blackstone" and other vaudeville personages. He has beautiful, but unknown guests at his opulent parties, his library has real leatherbound books, his car possesses mythological characteristics with its "fenders like wings," and its fenders that reflect the light. Gatsby, too, creates an aura of luxury and charm that has no history behind it. He is seen with unsavory characters such as Meyer Wolfscheim, but appears at a party in white flannels with a golden tie. He claims to have visited the capitals of Europe--Paris, Venice, Rome--yet he possesses an absolutely loyal heart. Jay Gatsby is an enigmatic character who bases his sense of worth upon the approval and love of Daisy Buchanan, and who
believed in the green light, the orgastic future that year by year receded before us.