McEnroe feared he might be the guy who peaked at 26. After Borg quit tennis, McEnroe dominated — top of his game — but wasn't truly happy, because being the best in the world wasn't as good as playing with someone who pushed you to greatness. He begged his biggest rival to come back. Borg told him: "If you're not number one, it doesn't matter if you're number two or number 100." McEnroe disagreed then and still does — number two is pretty damn good. Looking back at his failed talk show, the end of his first marriage, and projects that came and went, he stayed in it, kept trying new things, kept opening new doors.