I do remember losing the first five chapters of a novel, back in the early days of computers. It seems impossible, but, after I got over the shock, I also remember remembering every single word. Of course, I have no way to prove this. And the novel remains unfinished. Actually, after the first fifty pages, I wrote the rest of my outline as a screenplay, which produced a finished story, but much more confusion. Maybe my computer was trying to tell me something.