Here’s another installment of the best advice that some of our nation’s top business leaders ever received.

Intel Chairman Andy Grove says the best advice he ever heard came from his favorite professor at the City College of New York, Alois Xavier Schmidt, who said, “When everybody knows that something is so, it means that nobody knows nothin’”.

Xerox CEO Anne Mulcahy turned this advice from Albert C. Black, Jr., president and chief executive of On-Target Supplies & Logistics, into a mantra:  “Think about it this way:  You gota’ do three things.  First, get the cow out of the ditch.  Second, find out how the cow got in the ditch.  Third, make sure you do whatever it takes so the cow doesn’t go into the ditch ever again.”

Movie and TV Producer Brian Grazer has collected advice from about 1,000 people. Every month, he creates a new list of people to interview, from Isaac Asimov to Eliot Spitzer.  Grazer built his career on a piece of advice from two MCA executives, Jules Stein and Lew Wasserman. “You need to have leverage.  Since you have none – no money, no pedigree, no valuable relationships – you must have creative leverage.  That exists only in your mind. So you need to write.  Put what’s in your mind on paper.  Then you’ll own a piece of paper.  That’s leverage.” To this day, Grazer’s power comes from nothing but ideas on paper.

Rick Warren, the minister and founder of Saddleback Church, learned at the feet of management guru Peter Drucker.  On thing Drucker taught him is that results always show up outside your organization, not inside.  Most organizations in trouble scramble to restructure internally, but that’s not where to focus. “All the growth is on the outside,” Drucker told Warren, “From people who are not using your product, not listening to your message and not using your services.”

Adapted from “The Best Advice I Ever Got” Julia Boorstin, Cora Daniels, et al, Fortune Magazine.