Look at advertising: its sole function is to make us feel that certain things are missing from our lives. So today it’s possible for someone to feel poor if they don’t have air-conditioning or a flat-screen TV in a way that they wouldn’t have fifty or even ten years ago. Our sense of what it is to be reasonably well-off keeps changing, keeps risingeven though all of us are much better off than people were hundreds of years ago. But no one compares themselves to someone who lived three-hundred years ago or to someone in sub-Saharan Africa. We take our points of reference from those around us: our friends, our family. These are the people who determine our feelings of success. Which is why Rousseau wrote that the best way to become rich is not by trying to make more money, but by separating yourself from anyone around you who has had the bad taste to become more successful than you. It’s a facetious point, but it’s also a serious one. Feelings of wealth are relative.