I was once somewhat obsessed with Orange Grove Tool Sheds and Utility Boxes of Oliva, Spain. I photographed thousands over the course of just a few months.
Joe Eszterhas, the screenwriter of Basic Instinct, Flashdance, Betrayed, Music Box, and many others, once said that all his screenplays discuss the same thing. If you've seen these films, you'll know that they're quite different from one another, so it's a rather curious comment. Then he said, and I'm paraphrasing, "But I wasn't aware of it. It was someone else who pointed it out to me, the theme that I return to over and over again: Can you really know the one you love?" Indeed, that is what all those films are about.
I once heard author and Nobel Prize winner Patrick Modiano say that he writes the same book over and over again and that he likes to think of himself as a photographer with one subject. Before exploring them again, he just moves the camera to see them from another angle.
I like when artists do this. When they repeat themselves without being repetitive. It seems to me that this is what Seth Armstrong is doing with his urban landscapes:





Wonderful stuff. More on Armstrong's site.