Oliver Burkeman explained this in his book Four Thousand Weeks: Time Management for Mortals: “One critical aspect of the radical incrementalist approach, which

Oliver Burkeman explained this in his book Four Thousand Weeks: Time Management for Mortals: “One critical aspect of the radical incrementalist approach, which runs counter to much mainstream advice on productivity, is thus to be willing to stop when your daily time is up, even when you’re bursting with energy and feel as though you could get much more done. If you’ve decided to work on a given project for fifty minutes, then once fifty minutes have elapsed, get up and walk away from it. Why? Because as Boice explained, the urge to push onward beyond that point ‘includes a big component of impatience about not being finished, about not being productive enough, about never again finding such an ideal time’ for work. Stopping helps strengthen the muscle of patience that will permit you to return to the project again and again, and thus to sustain your productivity over an entire career.”