The high-potential employee proves to their employer that they are not just going to excel in their current role, but also push themselves to continually improve, upskill, and prepare themselves for their next role. This means they take on new and different responsibilities. It means they aren't afraid of lateral moves if they have a chance to master new skills. It means they actively solicit feedback from others to understand where their weaknesses lie. And, it means they learn on their own time.