Every big thinker who's made a difference in our lives, from Thomas Edison to Bill Gates, has had a high degree of mental toughness—or what you might call a thick skull. It isn't just about being stubborn, although that's part of it. These tough-minded sorts make for great leaders and entrepreneurs because they keep moving toward their goals despite ridicule from naysayers who can't appreciate what they're trying to achieve. But mental toughness isn't necessarily something we're born with, as many believe. It's a set of characteristics we can all learn. Here are some habits the most tough-minded leaders have developed.
