One of the panelists at the keynote on the last day of SITE made a really interesting remark. He said (in my own words), your perspective about the glass being half empty or half full depends on whether you're drinking or pouring. I don't know if he meant for this remark to be poignant, but I have really been thinking about it a lot. I guess the difference, to me, comes down between giving and receiving. If a person spends a lot of their time receiving and expecting from others, circumstances would naturally be viewed as falling short of his or her needs and expectations. I have known quite a few people like this, and honestly, I have been this person on many occasions. When your focus is on what you are (or aren't) getting, there will always be something missing.
On the other hand, people who spend more of their time, talents and energy giving tend to see the world in terms of what they can give and be for others. It makes sense that this sort of person would not spend a whole of time thinking about what he or she is not getting.
It seems the common view is that perspective is the starting place. A person has his or her worldview, and they act based on that perspective. But I'm starting to think that actions, whether focused on helping others or yourself, influence perspective, and this makes the daunting task of improving a pretty self-centered worldview not so impossible. A very wise person once said, "If your first concern is to look after yourself, you'll never find yourself. But if you forget about yourself and look to me, you'll find both yourself and me." I'm glad to have been reminded of that in the most unlikely of places.