Where does free will end and destiny start?

It's a question that has been around for centuries.  Where does our autonomy stop and destiny take over?  Are we in charge?  If so, how much control do we have?  Or are we simply puppets acting out someone else's script?

The most convincing answer I've found in my search to understand these opposites comes from Neale Donald Walsch.*  He likens each human life to a car trip with a GPS: it's an evocative image!  We have free will to choose any direction, any road that appeals to us.  And, we also have an end destination, that end destination is the experiences we chose for ourselves before we incarnated.

On route, we can choose to go down country lanes or stick to the motorway, yet we will always drive through the towns that we had planned to visit before we left home.  The wisdom of the universe is so subtle that each time we make a new decision, our soul recalculates our route to ensure that we have both the experience we have consciously chosen in that moment, as well the experience we chose prior to incarnation.

This seems like the best of both worlds to me.  We have complete freedom and yet there are no mistakes.  We can't miss our destiny.  We don't have to blame anyone else or any unseen forces for our lives, nor do we have to limit ourselves.  We can make the most of every moment of life, fearlessly and joyfully.

*The Mother of Invention, 2010