We need to be able to trust Nick because he is the narrator of the story. Although he potentially could be an unreliable narrator, he provides us with a description of the action and the characters' behavior that does not give us much reason to question his account. We are being introduced to a strange, exotic world here, one of opulent wealth and glamor. At times, it can seem almost like a fairy-tale world. In fact, the picture of the American Dream that The Great Gatsby presents is precisely that for many in the story. Indeed, most of the characters in the book are, to some extent, delusional. We need a clear-headed, truthful guide to take us on a tour of this crazy world, in which nothing is as it first appears. It is absolutely essential that if we are going to understand this world and the people who live in it, we need to be able to accept the truth of whatever it is that Nick is telling us. He is our way into the rarefied world of West Egg and East Egg; he is an outsider, just like most of the book's readers. If Nick can give us a truthful account of what he sees, then we can gain a much better understanding of what happens in the story, making us more deeply engaged with the characters and their situations.