Can I suggest adding it to a "when I'm REALLY bored" list? ;-)
It took me years for Prolog to kick in and it did when I was trying to... optimize my taxes in a very complex context (e.g. where I live there's a VAT difference on ketchup depending if it's sold on the fresh hot-dog or wrapped one).
But since then I try to advocate and use it as often as I can. Mostly because paradigm is super fun to work with and refreshing after all day of working on "normal" languages.
I managed to actually solve all the programming tasks we were given (and as I was the only one to do so among my peers, many copied my solutions) - but if anyone then asked me to explain how I did it, I was at a loss. I basically stared at the screen until some sort of intuition hit, and if that didn't work, repeat the process until it does...
I guess the paradigm never really "kicked in" for me ;)