The correct answer to this open question is the following.
What the narrator revealed about himself based on the style he uses to tell his story is that he is modest and practical.
We are talking about the novel "Farewell to Arms" written by Ernest Hemingway in 1929. It was one of the most important novels that made him a prominent American writer. It refers to the times the author spent in the war front in Italy, during World War 1. The main character is Frederic Henry, a lieutenant in the Italian army that oversees the soldiers in charge of the ambulance. The story includes a romance between Henry and a nurse called Catherine Barkley.