In reflecting on Gatsby's temperment, Nick comments that Gatsby had "an extraordinary gift for hope" and that the "foul dust floated in the wake of his (Gatsby's) dreams" was the reason for Nick's disaffectation with the trials and triumphs of others.
Nick finds a variety of ways in which Gatsby's life and actions were shaped by eternal hope. At the end of chapter one, Nick observes Gatsby looking across the water near their shared boundary. Nick considers addressing Gatsby but changes his mind when he notes that Gatsby almost seemed to be "trembling" as he looked at "a single green light, minute and far way." Later, of course, we learn that the light is on the dock belonging to Daisy Buchanan, the ultimate goal of all Gatsby's hopes and dreams.
Gatsby creates a new personal history for himself in his dreams. He hopes to impress people in general and Daisy in particular with the more exotic, more accomplished background he gives himself. He dreams of the day when he and Daisy will be able to do more than talk in circles about what might have been. He never gives up hope that the Great American Dream can be his.