Majority of Gatsby stories he tells people about his background are falsified. He uses others and gossip to transfer this false persona to win Daisy back. Affairs and Gatsby attempt to recreate the past also lead in this theme. With very little people in the book known to be truthful it's hard to guess who is truly honest.

-Wealth
The idea of wealth consumes those who weren't born into money like Myrtle and Gatsby. The constant chase of money ultimately leads Gatsby to his death. The wealth aspect ties directly into social stance which played a big role for Gatsby and Daisy's relationship.
-Society and Class
Society and Class played a big role with the book and story. Tom and Daisy were upper class living in East Egg, Nick was middle class who lived in West Egg, and then George and Myrtle lived in the Valley of Ashes and were the lower class. Gatsby is hard to place since he has money and lives in West Egg but has a low social standing. Gatsby chased the idea of being a powerful in social standing and class wise. The weight of power from social standing is very influential on the characters and how they interact with each other.
-Memory and the Past