Effective habits are internalized principles and patterns of behavior. They are the intersection of knowledge, skills, and desire.
My favorite sentence in this chapter was "Happiness can be defined, in part at least, as the fruit of the desire and ability to sacrifice what we want now for what we want eventually" (48). This is so true. Let's say you find out you need to lose 20 lbs. to pass height/weight for the upcoming APFT. You really want to pass the APFT. Then, in the dining hall that night, you really want to eat a brownie with mint chocolate chip ice cream on top. What do you do? It's obvious that in order to be happy, you'll have to sacrifice what you want now (the mint-chocolately goodness) for what you want later (passing a PT test).
Covey talks a lot about the progression from dependency to independency to interdependency. This is good stuff. Our culture values independency so much...I think many people do not even realize that being interdependent is better. Covey says, "Ironically, you'll find that as you care less about what others think of you, you will care more about what others think of themselves and their worlds, including their relationship with you" (61). Awww, cute, we need to care about each other.
He also goes into detail with the P/PC Balance. In order to be effective humans, we need to balance actual production with production capability. You cannot just worry about results all the time--methods and preparation are important. (ps--In the long run, obviously, putting time in PC increases P anyway.)