When you write a book, you live in that book for the duration of its creation; become friends, or maybe enemies with the characters. You may think you're in charge of the process, but sometimes there are forces at work within the imagination that we can never really understand.
Have you ever written a piece and then read it back and wondered where it came from? Or drawn an illustration that you can never recreate, because you're not really sure how you drew it in the first place? That is the magic of the imagination and of creativity - now if I can just harness that magic into promoting my book, instead of researching promotion only to fall into the clever marketing traps set by others and end up buying a product instead of selling one - but hey, there are worse things than buying another book, so I forgive myself...
