What is the main theme of "A Painful Case" and how do you describe that theme?

In Dubliners by James Joyce, the story "A Painful Case" deals with a man who is seriously stuck in his ways and in the way he wants his life to go. However, it is precisely his inability to be flexible and his inability to change what leads him to lose his one chance at love and happiness.

Hence, the main theme is the need to accept change as an essential survival skill.