I originally put a pre-order date on my book when I was updating to KPD, the reason was motivation. No doubt you heard of Turner still applying paint to his canvasses as they hung in the gallery, well I find it difficult to stop tweaking my work too. Like checking the house twice before I leave, locking car at least twice before walking away, and the treble-checking everything when going on holiday! Of course finding something starts whole process again and I can always find something in my writing to tweak.
On this date twenty-five years ago I gave birth to my first child. Launching a book is a lot less physically painful, but still churns up a load of emotions.