When I was at IBM, I spent some time in the Executive Resource program, which is designed specifically to prepare someone to be a CEO. The program includes classes by top executives and military officers who either were CEOs themselves or were on the short path to becoming a CEO.
Outside the Executive Resource program, I've also met or studied a number of CEOs, including Thomas Watson Jr., Steve Jobs, Louis Gerstner, Bill Gates and a variety of others. Each had unique skills, and no one was perfect in all things-though Watson came closest. Some were founders, some the sons of founders and some hired to fix broken companies, but each stood out in succeeding where peers in the same period failed.