In the last 15 years, the science of mind wandering has become a popular topic of scholarly study, thanks in part to advances in brain imaging. It turns out that our brains are wily, wild things, and what they do when we're not paying attention has major implications for our happiness. In 2010, Matt Killingsworth, then a doctoral student at Harvard University, designed an iPhone app that pinged people throughout the day, asking what they were experiencing at that very moment. You'll want to know his surprising discovery!
