1) He was a classical music maven.

Although I knew his mother had been an aspiring opera singer and had taught piano and voice in the Hemingways' Oak Park, Illinois home, I didn't realize that classical music was Hemingway's go-to soundtrack for relaxation and distraction. But when shells were whistling over the Hotel Florida in Madrid, where he and Martha Gellhorn were staying during the Spanish Civil War, what did Hemingway put on the Victrola to drown out the bombardment? Chopin's Opus 33 mazurka, number 4, and the ballade in A-flat minor, opus 47.

2) He was an agent of the KGB.

In public Hemingway had always strenuously resisted the idea of writing anything from "a Marxian viewpoint" â?? something he derided as "so much horseshit." But in 1937, when he was in Spain covering the Civil War for the North American Newspaper Alliance and writing the script for Joris Ivens's documentary film, The Spanish Earth, Ivens had tried to enlist him as a propagandist, and possibly more, for the Communist Party, which had been supporting the Spanish government against Franco's rebels. And according to internal KGB files studied by a former Soviet agent, Alexander Vassiliev, Hemingway was recruited by the KGB in 1941 and given the code-name "Argo." It was hoped he could report on Nazi activity in Cuba and the Caribbean during World War II, but he never generated any useful intelligence and his cover was terminated in 1950.

3) He couldn't cook paella.

In April of 1937, at a Rioja-fueled lunch party at the Madrid restaurant Botin, a spot Hemingway loved (and had celebrated in The Sun Also Rises), the writer insisted on leaving the table â?? where the company included the photographer Robert Capa and Capa's beautiful girlfriend and professional partner Gerda Taro â??- and going into the kitchen to help prepare paella. "Less skillful in the kitchen than at the typewriter," was the tactful verdict of the restaurant's owner, Emilio Gonzales.

4) His affair with Martha Gellhorn was less than a great romance.

He might have run off with Gellhorn to Spain, beginning an affair that culminated in marriage three years later, after he divorced his second wife, Pauline; but apparently the Gellhorn-Hemingway romance could have used some couples therapy. Gellhorn later claimed her "whole memory of sex with Ernest [was] the invention of excuses and failing that, the hope that it would soon be over." Which it was, by 1944, when Gellhorn scooped her husband by getting a ride on a hospital ship to the D-Day beaches while he gazed at the coast through binoculars from the deck of an attack transport.

5) He originally began the manuscript of his most successful novel, For Whom the Bell Tolls, which draws on his experience in the Spanish Civil War, in the first person.

He changed his mind, choosing the detachment of a narrative in which the protagonist is "he," not "I." It was the best and most truthful decision he could have made. To understand why, of course, you have to read the book. Or books. His, and mine.