20,000 ft - Areas of responsibility

I'm a recent adopter of GTD. I've been focusing solely on the project and next action level for about three months. It's been great at helping me get a lot of niggling actions and decent projects knocked out, but it hasn't helped me at all with the big life-goal kind of stuff. I decided to try out the vertical map, mimicking the one Patrick Rhone posted here some time ago.

I've been going through it, and it's going pretty well. I can see how using and reviewing this can help me generate a lot of projects and actions to achieve my larger goals, but I'm stuck at the 20,000 ft level. I just don't get it. In Patrick's example, it's just a list people and what he does with them. What's the point?

Does anyone have an example of what they do with this info to help them get stuff done?