According to this model, you must first become the kind of person who is able to achieve your outcome, and then do the actions that are required to enjoy the fruits of your efforts. Since most of our behavior is designed to achieve certain outcomes (goals and desires), it is very important to define these outcomes in advance. For example, simply saying "I want coffee" will probably leave you disappointed when you get a tiny cup of cold, weak, overly-sweet coffee, when what you really wanted was a big cup of steaming-hot mocca java with a touch of milk and no sugar (see the difference and the importance of being specific?)
If you know where you want to be, you will be in a better position to construct the right maps to guide you. Better yet, you will be able to come up with new, easier, or faster ways to get there. Goals can go a long way in helping you achieve excellence.