There are many themes that are in this story. The themes are as follows: Versions of Reality, Dissatisfaction, Men and Masculinity, and identity. Versions of Reality is because Walter Mitty is not satisfied with his life so he creates other realites so he can be satisfied with himeself. This leads into that he is dissatisfied with his life, but not willing to act in order to change it. Men and Masculinity is in the story because Mitty, in his everyday life does not live up to his idea of a manly person. Identity is the final theme and is shown in the story because we do not know how much of our identity comes from the opinions of others and how much comes from ourselves.
The main theme though is how Mr. Mitty is dissatisfied with his life, but is not willing to work to change it for the better. This is shown in how if he wants to be happy with his life he has to not live in his real life and create his own reallity were everything is perfect in his eyes. While this is a temporary fix it is not the best, in fact it is probably the worst. The correct way is to put forth the work and change it so you can live the life you wish to live. These are the themes of The Secret Life of Walter Mitty.
The main theme though is how Mr. Mitty is dissatisfied with his life, but is not willing to work to change it for the better. This is shown in how if he wants to be happy with his life he has to not live in his real life and create his own reallity were everything is perfect in his eyes. While this is a temporary fix it is not the best, in fact it is probably the worst. The correct way is to put forth the work and change it so you can live the life you wish to live. These are the themes of The Secret Life of Walter Mitty.