I love it when a Pixar or Disney film has strong, uplifting messages behind it. Brave is one of those films and this quote is a brilliant reminder that we are the managers of our own life. No, you cannot control everything that will happen to you, but you can choose how you react and deal with it.
It is actually a very brave thing to do, to start to take ownership of your own life and what you do with it. But taking control is how to start finding happiness, rather than letting life control you.