This article takes a look at the mental strength of athletes and offers advice on how to improve one's game through the teachings of the ancient Greeks. Drawing inspiration from the Stoic philosophies, the article proposes three ways to be mentally tougher: by focusing on the things that can be controlled, by adjusting to the situation and not reacting, and by developing grit and perseverance. Furthermore, the article emphasizes that mental strength is not only important for athletes, but that it is actually essential for a successful career.