If the executive lets the flow of events determine what he does, what he works on, and what he takes seriously, he will fritter himself away “operating.” He may be an excellent man. But he is certain to waste his knowledge and ability and to throw away what little effectiveness he might have achieved. What the executive needs are criteria which enable him to work on the truly important, that is, on contributions and results, even though the criteria are not found in the flow of events.
From “The Effective Executive: The Definitive Guide to Getting the Right Things Done”
by Peter F. Drucker