Rich Karlgaard: Peter F. Drucker was born 95 years ago-can it be possible? Now confined to a walker and nearly deaf, Drucker stopped giving press interviews about a year ago. But in late October he granted an exception to FORBES.

Peter Drucker: I’ve seen a great many people who are exceedingly good at execution but exceedingly poor at picking the important things. They are magnificent at getting the unimportant things done. They have an impressive record of achievement on trivial matters.

Leaders are purpose-driven. They know how to establish a mission. And another thing, they know how to say no. The pressure on leaders to do 984 different things is unbearable, so the effective ones learn how to say no and stick with it. As a result they don’t suffocate themselves. Too many leaders try to do a little bit of 25 different things and get nothing done. They are very popular because they always say yes.

A critical question for leaders is,”When do you stop pouring resources into things that have run their course?” The most dangerous traps for a leader are those nearsuccesses, where everybody says if you just give it another big push it will go over the top. One tries it once, one tries it twice, one tries it a third time. But by then it should be obvious this will be very hard to do.

When you are the chief executive, you’re the prisoner of your organization. The moment you’re in the office, everybody comes to you and wants something. And it’s useless to lock the door. They’ll break in.Get a secret office elsewhere.

Organizations fall down when they have to guess what the boss is working at, and invariably they guess wrong. So the CEO needs to say, “This is what I am focusing on.” Then the CEO needs to ask of his associates, “What are you focusing on?” Ask your associates, “You put this on top of your priority list-why?” Make sure that you understand your associates’ priorities, and make sure that after you have that conversation you sit down and drop them a two-page note: “This is what I think we discussed. This is what I think we decided. This is what I think you committed yourself to within this particular time frame.”

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