We all have a vast number of areas in which we have no talent or skill and little chance of becoming even mediocre. In those areas a knowledge workers should not take on work, jobs and assignments. It takes far more energy to improve from incompetence to mediocrity than it takes to improve from first-rate performance to excellence.
Peter Drucker, Alan Kantrow, Rick Wartzman, Julia Kirby (2016). “Get the Right Things Done: The Drucker Collection (6 Items)”, p.12, Harvard Business Review Press
