"The Secret Life of Walter Mitty" is Thurber's best-known short story. Walter Mitty has become a well-known character in American fiction. The tenth edition of the Merriam Webster Collegiate Dictionary defines a "Walter Mitty" as "a commonplace unadventurous person who seeks escape from reality through daydreaming." Walter Mitty, the average, ineffectual American is a recurring character-type in Thurber's fiction. Critics refer to this type of character as the "Thurber male."

However, critics are divided on how to interpret this Thurberian character. On the one hand, Richard C. Tobias's The Art of James Thurber views Thurber as a cerebral comic writer, whose protagonists defeat humdrum reality with their imaginations. On the other hand, Walter Blair and Hamlin Hill discuss Thurber's bleak comic sensibility in their book, America's Humor. Characters like Mitty, Blair argues, let their neurotic fears defeat them, and are unable to cope with the world...