A question.

Why is it that, while re-writing your current epic thriller, you always get a KILLER idea for a NEW book, which is so MAGICAL and AWESOME, and TERRIFIC, that you just want to throw the book you are writing NOW into the back of the wardrobe where it belongs with all of the other discarded items, and start this NEW, better story which is bound to be a bestseller?

This new idea is TOTALLY commercial and High Concept.

You can already SEE the movie for this NEW idea.
You can hear the agents and publishers hammering on your front door, any door, fighting for the chance to carry this NEW book.

And NOT the book you know that you have to finish, and which, until yesterday, you thought was pretty good. It only needs another couple of weeks of 10 hour days of slog, re-structuring and complete change of opponent motivation etc to create a decent second draft.

While, all the time, this new cunning idea- which has amazed even you, goddess of genius, by how clever and unique it is- is lurking on a note card. Tempting you away from the true path of the righteous professional writer.