As leaders encounter entirely new kinds of challenges and responsibilities, they find that they have the strength and resources to meet these challenges. For example, some first-time leaders ultimately learn that they have a gift for leading and inspiring others. Others find that they're especially talented at gauging others' motivations and values. Each time you make something happen as a leader—whether it's shaping your group's culture in positive ways, helping someone master a new task, or assembling a top-notch team—leaders expand their abilities. They become more seasoned, experienced, and confident leaders, and have a sharper awareness of their own strengths and areas for improvement. Not only do they learn more about themselves as they progress in a leadership role; they also learn...