What story of his background does Gatsby first tell Nick?

Gatsby tells Nick both his parents were wealthy but are now deceased, and they lived in the Midwest. He was educated at Oxford, and then he inherited all of the family's money and lived very well in the cities of Europe. All of this time, Gatsby said he was trying to forget something bad that had happened in his life, and he promised to tell Nick about it later that day. Because of that experience, Gatsby said he had wanted to die in the war, but was instead promoted and decorated for bravery. Later, Nick realizes that the only thing that was true of this account was that Gatsby had been at Oxford.