Part of the novel's commentary relates to how the romantic and expansive visions of America (and Americans) fits or fails to fit into the modern world. Gatsby, described as believing in “a promise that the rock of the world was founded securely on a fairy's wing,” is a dreamer who achieves everything but his dream.
Dreaming of romance with Daisy, Gatsby nearly captures a life-long hope, but ultimately fails.
Fitzgerald layers his main character’s supposedly pure love with cynicism toward the world and toward his own potential.
This cynicism is critical to understanding the message of the novel. It is also essential to grasping the "greatness" of Gatsby as a character.
The fraud, Gatsby, is also innocent enough to continue to believe in true love. The bootlegger is honest in important ways - in ways that his cynicism cannot touch - yet he is engaged in an illegal enterprise, a rather enormous lie, while attempting also to steal away another man's wife.
Gatsby is a dreamer, capable of continued innocence despite circumstances that would seem more than powerful enough to destroy this innocence. The hope that he embodies is, symbolically, larger than him. Gatsby is participating in an American hope - for self-improvement; achievement; self-determination. He believes as the country once believed that with enough persistent effort, anything can be brought off.
This dream, challenged by the narrative, is central to the myth that Gatsby adheres to as a person and expresses as a character.
Essentially these words are at the heart of Gatsby's quest. He spends the entire novel with the hope of fulfilling his dream of happiness, which he feels is Daisy. His actions and accumulation of wealth go hand in hand with his pursuit of this dream. The fact that he is unsuccessful is a statement being made by Fitzgerald.