I haven’t experienced this very much so far, until the day before yesterday, that is. I’m currently working on another book that’s not a part of the After Earth series. In fact, when I first started writing this story, I was writing it by hand, as we had no computer yet, and I didn’t think it was typewriter deserving at that point. I have a map of the mythical Arizona town, a list of characters, and an approximate time-line laid out. The writing began prior to 1987, which was when we got our first computer: An Apple IIGS. At that point, I used the computer for the story.
I printed the whole thing on that accordion-folded, dot-matrix printing paper, and that was it. After it was done, I didn’t know what to do with it, so it went into the file cabinet—and there it languished. Now, 28 years later, all six books in my After Earth series were written, and while editing books five and six, I had some extra time. So, out came the old novel—a science fiction/horror story.