Am currently roughing out the history of the world I'm creating (or discovering, rather), and realizing there are all sorts of bits that could easily turn into very hefty books (accidental empire making! Lewis & Clark, only with magic and a bazillion tropical islands! the fall of said empire to magical zombie-vampire-ghosts! the raising of a gigantic, invisible, partially-permeable wall that's built mostly over ocean! spying on an immortal imperial family that can steal the appearance (and memories!) of other people!) so I don't need to worry about ever running out of story possibilities ever. And that's looking at just one people group/chunk of geography. The possibilities are dizzying.