Your life is the sum result of all the choices you make both consciously and unconsciously. If you can control the process of choosing you can take control of all aspects of your life. You can find the freedom that comes from being in charge of yourself.
I like to write sad songs. They're much easier to write and you get a lot more emotion into them. But people don't want to hear them as much. And radio definitely doesn't they want that positive uptempo thing.