I've always had a fascination with the unseen world and how we explain it, whether through science or myth and folklore. My Mom was born in Ireland and my Granny would tell us that the wee folk definitely existed. With that type of grounding, how could I not believe there were parallel worlds, even if we couldn't see them.
Later, when I was working as an editor for publications from the Saudi embassy, I was exposed to Middle Eastern history and myth. Turns out, they believe in an unseen world, too. Namely, genies.
Had to find out more so I did a lot of research into the djinn/jinn/genies. Armed with magical worlds swirling in my head, I just had to create some characters to release them. (guess that makes my head a magic lamp and, yes, I frequently rub it - especially if I'm stuck on a scene.)
You write that you haven't read much about genies and that might be because there's not a lot of fiction that takes them "seriously" (other than that puffy blue guy). Rachel Caine includes genies in her Weather Warden series and there are a few others, but just a few.
I hope you'll check mine out. Let me know if there's any other jinn trivia you'd like to know about....