I don't think it's useless. It's stupid because to some extent I know these places don't exist but my mind thinks of them as being so real sometimes I can't tell the difference between my memories of them and those of places I've actually been to.
When I was a very little kid, like three or four, I used to have dreams with recurring characters in them. The people I knew in my dream world were very real, very vivid, but they did not exist in reality. They were not people I knew in my waking like, not even
similar to anyone I knew. Not even composites of anyone I really knew.
My aunt said I was an old soul, and those were maybe people I'd known in my previous life. But I don't think so. They seemed thoroughly modern. They wore regular clothes. In my dreams, we met at real places, places I was familiar with from my waking life.
This sense of leading a double life- one dream, one waking- continued for a number of years, until I was maybe seven or eight, at which point my dreams started to become less vivid and more fragmentary, and I was able to remember less about them.
Eventually, these friends I had in my dream life stopped making appearances in them. I dreamed about actual people, real-life people, when I dreamed about anyone.
I think my stories- my writing- comes from the same place your art does.
Some alternate universe that exists in my mind. Some microcosm.
As an adult, I've never been able to access it as freely as I did when I was young, though.
That's a skill you'll want to hold on to, if you can.