In high school, Jeremy Lin was such a good basketball player that he let it go to his head. He got a big ego and was often kicked out of practice. One day at a pick-up game, he broke his leg. He had to sit out and watch the rest of his team play for the championships. From that day forward, he vowed he would “never not work hard.” Being on the sidelines taught him to stop taking the sport for granted and find new depths of mental toughness.