“This concept upends the way most people think about their subjective experienceof life. We tend to place a lot of emphasis on our circumstances, assuming that whathappens to us (or fails to happen) determines how we feel. From this perspective, thesmall-scale details of how you spend your day aren’t that important, because whatmatters are the large-scale outcomes, such as whether or not you get a promotion ormove to that nicer apartment. According to Gallagher, decades of research contradictthis understanding. Our brains instead construct our worldview based on what we payattention to. If you focus on a cancer diagnosis, you and your life become unhappy anddark, but if you focus instead on an evening martini, you and your life become morepleasant—even though the circumstances in both scenarios are the same. As Gallaghersummarizes: “Who you are, what you think, feel, and do, what you love—is the sum ofwhat you focus on.”