R. Keith Sawyer

“people are more likely to get into flow when their environment has four important characteristics. First, and most important, they’re doing something where their skills match the challenge of the task. If the challenge is too great for their skills, they become frustrated; but if the task isn’t challenging enough, they simply grow bored. Second, flow occurs when the goal is clear; and third, when there’s constant and immediate feedback about how close you are to achieving that goal. Fourth, flow occurs when you’re free to concentrate fully on the task.”
― Robert Keith Sawyer, Group Genius: The Creative Power of Collaboration