Are there people you just don't feel like having fun with?

I find myself watching some of the frivolity here and feeling unmoved to participate. I don’t know if I’m just not in a mood for fun, or if it isn’t my kind of fun, or if the people are people I don’t want to play with.

If there are people you don’t feel like having fun with, why is that? Please, nothing personal. Just the kinds of reasons that make you feel unamused by a person.

More generally, what puts you into a frame of mind where you do or don’t want to play?