How truthful was Gatsby when he relayed the story of his life to Nick? Why does Fitzgerald tell the story of James Gatz now?

In the novel The Great Gatsby, the character Gatsby tell his life story to Nick. Gatsby is not completely honest with his story as he may relay his life’s story, but he doesn’t include all the fine important details that go along with it. In fact Gatsby didn’t even grow up with that name, he grew up as James Gatz, a young farmboy. When he finally made it to college, he only lasted two weeks, before he finally decided it was best for him to drop out irrationally. It was impressive how Gatsby even managed to get into a college, as his family did not have much money, and lived a far from glamorous life. Gatz worked as a low class citizen, digging for clams, and fishing. Gatz eventually befriended another fellow fisherman named Cody, who when passed away, left Gatz with 25, 000. It was after this that Gatz decided he wanted to spend the rest of his life trying to become a wealthy man. In the novel The great Gatsby, the main character is portrayed as a well put together man, though he has had his troubles. I believe it is the authors idea, to stick with the character and not have him explain his troubled past, but instead explain it to us in a creative way, so you still have the feeling of Gatsby being a well put together man, but we still learn about his past.