Level 5 leaders are differentiated from other levels of leaders in that they have a wonderful blend of personal humility combined with extraordinary professional will. Understand that they are very ambitious; but their ambition, first and foremost, is for the company's success. They realize that the most important step they must make to become a Level 5 leader is to subjugate their ego to the company's performance. When asked for interviews, these leaders will agree only if it's about the company and not about them.

Just because a company falls doesn't invalidate what we can learn by studying that company when it was at its historical best.

The best CEOs in our research display tremendous ambition for their company combined with the stoic will to do whatever it takes, no matter how brutal (within the bounds of the company's core values), to make the company great. Yet at the same time they display a remarkable humility about themselves, ascribing much of their own success to luck, discipline and preparation rather than personal genius.

You need self-control in an out-of-control world.

For no matter what we achieve, if we don't spend the vast majority of our time with people we love and respect, we cannot possibly have a great life. But if we spend the vast majority of our time with people we love and respect - people we really enjoy being on the bus with and who will never disappoint us - then we will almost certainly have a great life, no matter where the bus goes. The people we interviewed from the good-to-great companies clearly loved what they did, largely because they loved who they did it with.

The critical question is not whether you'll have luck, but what you do with the luck that you get.

Creative leadership impact increases in your 50's. When I turn 50 I want to say, "Nice start!"