In what ways is A Farewell to Arms auto-biographical?

There are many obvious similarities between the narrator of the novel, Frederic Henry, and its author Ernest Hemingway. Both were wounded while serving as ambulance drivers in Italy during the First World War. Neither felt much attachment to his family or particular allegiance to any ideology at the time. Like his narrator in the novel, Ernest Hemingway was a connoisseur of experiences. The fictional Catherine Barkley is an acknowledged characterization of a nurse Hemingway met while recuperating from his wounds. Unlike the real-life Sister Agnes Hannah von Kurowsky, however, who spurned young Ernest’s advances, the fictional Catherine Barkley falls deeply in love with Frederic. Her death in the story, however, can be taken to have brought the same lessons to Frederic as Hannah’s refusal and his experiences in the war brought to Hemingway.