If you’re like most people, it’s easy to assume that a better life comes from adding more. More house. More travel. More experiences. Maybe even a higher-paying job. With the exception of the job itself, every one of those “mores” requires more money, which quietly reinforces a powerful belief: If I had more money, I’d be happier. For a moment, that can even feel true. The new thing arrives, the trip happens, the upgrade feels great. And then life settles back to normal. We return to our old...