The question is where worry comes from. Sometimes there's an external force contributing to worry, like having to pay rent or living in an apartment with a rabid bulldog. Other times, the worry comes from something inside, like wondering why you don't go out as much as other people or why your house isn't bigger. The internal worries are ones you can fight without necessarily changing your life, because they're fictions in some way.

In this case, he's been told that he isn't happy unless he's feeling a certain way, and now that he's not feeling that certain way, he decides he must be unhappy. The problem's circular.