I Had No Idea She'd Do That

The first time a character took over and started writing her story herself, it blew me away.  Seriously, it was an 'Oh my God' moment.

Oh sure, I'd read what other writers had written about when it happened to them.  But you have to experience it for yourself to truly understand the amazement it brings.

But when it happens to you, it's a sign that you've reached the point where you deeply understand your character's personality and motivations.  The point where you don't have to try to figure out what your character would do next.  The character tells you.  And sometimes it takes the story in a direction you didn't expect.