In The Secret Life of Walter Mitty, James Thurber gives us something much more important than laughs: he gives us a brief but penetrating glance at human nature. The story focuses on Walter Mitty, an ordinary man, with the habit of daydreaming. Walter will simply forget anyone around him and become someone else; a navy pilot, a surgeon, a suspect for murder, a World War II pilot. In these dreams, he is always the hero, a character of bravery and valiance. In real life his wife often interrupts these fantasies, and he resents her for this. His wife, on the other hand, thinks that he may be ill, as he tends to drift off. She sees his fantasies as a failing on his part, while he uses them to escape reality.
Perhaps the most important theme of the story is that these fanatics may not be bad, quite to the contrary, they may be very good. James Thurber thinks that daydreams provide an escape from reality, and a valuable way to make an otherwise boring day livable. The ending to Walter Mitty reflects this opinion. Mitty ends the story returning to the real world, though much better for the break. Consider this quote:
"He took one last drag on his cigarette and snapped it away. Then, with that faint, fleeting smile playing on about his lips, he faced the firing squad; erect and motionless, proud and disdainful, Walter Mitty the Undefeated, inscrutable to the last."