Another good question.
Once we know WHY (also called 'knowing what we want'), we are in a better position to start doing something about it. As an example, lets say that what we want is to travel and experience faraway places and cultures. Knowing that is our goal makes it easier to select which places are most desired, then find ways to get there, things to do there, and how to fit it into our available time, money and effort.
By having a simple, effective way to deal with things, we are well on our way to a better me.