Once, as part of a writing exercise, I wrote out an interview with one of the characters in a novel that I was writing. Oddly enough, even though I was writing it, I wound up kind of losing control of the situation; the character ended up berating me for not fleshing him out more, and asked me a number of uncomfortable personal questions, neither of which were things I had had the slightest intention of having him say. You can call it logical progression or the subconscious taking over if you want, but it was pretty damn eerie at the time, I can tell you.