The third chatper in the book discusses the varying driving forces behind peoples life. For example, fear, posessions, acceptance, etc. It reminded me of one of the questions they asked me when I interviewed at Boeing: "What motivates you to do your best work?" It was a question I wasn't really prepared for - it definitly caught me off guard. I had never really stopped to think about that, at least not in that way. However, I think I got at least part of my response to the question right that day. My religious beliefs are a large part of what motivates me to do my best. Sure, there's other things too, like those three things I listed before, but those will only give you incentive to do just enough to obtain what you want, not necessarily your very best.
The author's point is that the purpose for our life should be our motivation for doing things. We should then trim out the things in our life that don't help us accomplish our purpose. This sound great, but I think you have to be careful then how you define your purpose. If you define it too narrowly, things are going to get missed. For example, if I say my purpose is to spread God's word to those people I work with, then my performance at work is going to suffer. Therefore, part of my purpose, at this time in my life, is to code and test software for the best military helicopter ever made - among several other things. Anyway, I'm curious to see how the author goes forward with this.