Disillusionment of the American Dream :

• Gatbsy achieves the American Dream, he becomes very rich (wants Daisy back)
• Gatsby thinks that his wealth will be enough to get Daisy back, but he never gets her
• Myrtle tries everything to be part of the upper class : she dies

Dissilusionment of the Upper Class :

• Nick tells Gatsby that he is worth more than the others
• Nick is expressing his disillusionment of Daisy, Tom, ...
• The Upper Class seems to have it all, but in reality they have nothing : everything is superficial
• Nick is disillusioned at the end of the novel (his transformation throughout the book) : he is disillusioned of his own original aspirations, doesn't want to be like Gatsby anymore
• Nick is disillusioned by the East : they are corrupt and careless people (relation with Jordan)