Worlds filled with Influencers, Coaches and Consultants aren't the best places to learn the most important skill of all: how to lead others. After all, your influence reaches much further than you'll ever know, through the people you interact with in your daily life and those they will go on to lead. You might as well set a good example. Not all leaders are born to lead. In fact, many have to learn from all the hard lessons and challenges life throws in their way. Sure, it's a lot more work to develop as a leader. But that long, hard road can take anyone -- even a headstrong kid from Chicago -- and transform them into the kind of people they had no idea they could ever become. Follow John Petrie in his journey from Marine Private to global security CEO, as he sprinkles philosophies inspired by amazing leaders in both his military experience and his private life. This is his playbook, and through it you'll see that there's no real secret to success, just a lot of life lessons to collect and skills to master. If you're ready to be a better leader, improve your performance in a group setting or even bulk up your interpersonal skills, there's no teacher like Petrie.