The life of Walter
Walter is a victim to the real world.
Firstly, Walter is a very imaginative person. In the 10 minutes it takes to read the story, he has 5 daydreams faster than anyone I know, including myself. The daydreams are always about unusual and exciting things.
Secondly, Mitty is childish. He is always daydreaming, which a grown adult shouldn't be doing as much as this man. He always daydreams about being a doctor, or a pilot. even a firing squad, or a defendant in a court.
Finally, Walt seems depressed. He daydreams to escape his life. He is always slow to do things and is not enthusiastic about many things. He says "Oh... Right." when he gives the man the car keys.
Overall, Walter is a target, and suffers to the real world because of how immature he acts.