Walter Mitty isn't doing so Pretty
The text structure defines the character of Walter Mitty as suffering from depression.
Walters wife controls him. She made him go to the garage and get the chains taken off. Walter has to go out and buy everything.
The attendent was rude. "Hey, better leave the key!" Walter's thought about that was "They're so d*** cocky."
He takes constant trips to day dreams. Everyone treats him badly. And he idolizes himself in his day dreams.
The text structure defines the character of Walter Mitty as suffering from depression