Once your brain has become accustomed to on-demand distraction, Nass discovered, its hard to shake the addiction even when you want to concentrate. To put this more concretely: If every moment of potential boredom in your lifesay, having to wait five minutes in line or sit alone in a restaurant until a friend arrivesis relieved with a quick glance at your smartphone, then your brain has likely been rewired to a point where, like the mental wrecks in Nasss research, its not ready for deep workeven if you regularly schedule time to practice this concentration.

Deep Work by Cal Newport