Having close access to ultra-successful people can yield some pretty incredible information about who they really are, what makes them tick and, most importantly, what makes them so successful and productive.
"Whenever you see a successful person, you only see the public glories, never the private sacrifices to reach them." – Vaibhav Shah
Kevin Kruse is one such person. He recently interviewed over 200 ultra-successful people, including seven billionaires, 13 Olympians and a host of accomplished entrepreneurs. One of his most revealing sources of information came from their answers to a simple open-ended question: