As Jay Gatsby stands in his yard looking at the green light on the dock of Daisy Buchanan's property in Chapter One of The Great Gatsby, there may be some doubt as to what all he desires; however, there is no doubt about what Jay Gatsby does not want. He does not want to be a poor farmer like his father. And, once he is called over to Dan Cody's boat, Jay Gatsby knows that he does want, what he perceives as "The American Dream." This American Dream is, of course, illusionary. But, Jay Gatsby pursues it as one does the Holy Grail.
For Jay, his perception and pursuit of the noveau riche is constant. He vies for lavish parties against those at East Egg; his house is resplendent; his pool as beautiful as a glacier lake. When Daisy comes to his house, he open drawers and pull out shirts of every color in order to impress her with his material acquisitions. His car is so magnificent that it takes on mythological proportions. But, above all this, as Nick remarks in Chapter Eight, Jay pursues Daisy as the chilvaric knights have sought the Holy Grail. For, in Gatsby's eyes, Daisy in her white car and dresses, is a purity personified and that which he seeks. In fact, it is the discrepancy betwen Jay's illusion of Daisy and all that she stands for and the reality of the Jazz Age which kills Gatsby.
Gatsby has devoted his life to building his identity and his fortune in order to woo and regain the affection of Daisy which he had prior to being shipped off to war. Many critics argue that his version of the American Dream has everything to do with re-inventing himself as a member of the gentry and eventually failing because it isn't just about money but about being born into it.
Gatsby hopes that the massive amount of wealth he acquires and the image of the generous and mysterious host who throws enormously lavish parties will get him on the same level as Tom but he falls short.