“When mastery is the goal, spending an exorbitant number of hours in one sitting will likely lead to burnout. We don’t go to the gym expecting to put on 20 pounds of muscle in a single, day-long workout. Instead, we do several short workouts a week, spread out over months. Our bodies need time to heal; our muscles time to grow. And the same goes for that muscle inside your skull. When trying to develop a new skill, the important thing isn’t how much you do; it’s how often you do it.”