A subtle point made my Peter Drucker is that management has very little to do with managing other people. He assigns people to people issues within an organization to the realm of leadership--which is a learned and not inherent trait. Management of resources is the major concern of all people, regardless of rank. Of all the resources in the universe, Drucker identified time as the most important, because for humans, there is a finite amount of it. He would give numerous examples of how people mis-use time, and more importantly, underestimate the time that it takes to do quality work.
Today, I'm wasting some time, but if I try to rush some things I'm working on, they'll leave the office half-done. I like to aim for 3/4 complete. 9/10 is a rare triumph.