Ernest Hemingway was famously masculine. We can see this in the topics he wrote about: all those fights and bullfights, all those wars, all that hunting and fishing. All this, it is thought, was overdoing it and must point to some deep insecurity in the man. Perhaps he felt that the conventional image of a writer as a person who doesn't do a lot more than sitting at a desk, not visibly contributing much socially or economically to society as a whole was unmanly and carried a certain amount of guilt and shame with it?
During the First World War, he was badly wounded, hospitalized, and fell in love with a nurse. He wrote a novel about a man who was badly wounded in the First World War, was hospitalised and who fell in love with a nurse. The Spanish Civil War and the Second World War followed as did books about his experiences in them. Now, how much can we draw on a writer's biography to explain his work? It should, l believe, be irrelevant to the judgement you bring to the merits of the individual work.
Biographies of writers can be fascinating, especially if they lived as hard and fast as Hemingway, but, unfortunately, these days many people prefer the biography to the actual work. It is odd that the very reason a person would want to read a biography of a writer - that the subject has achieved fame and distinction in his field - should be the excuse for not reading his works.