As I see it then, the formula runs something like this: a man must choose a path which will let his ABILITIES function at maximum efficiency toward the gratification of his DESIRES. In doing this, he is fulfilling a need (giving himself identity by functioning in a set pattern toward a set goal), he avoids frustrating his potential (choosing a path... See more
In short, he has not dedicated his life to reaching a pre-defined goal, but he has rather chosen a way of life he KNOWS he will enjoy. The goal is absolutely secondary: it is the functioning toward the goal which is important.