When you take charge of your mind, you take charge of your life. When you understand your thoughts, feelings, emotions, and desires, you can direct them to any end you choose.
Wisdom comes from taking the time to study yourself, to know why you are the person you are. Taking charge of your mind is a thoughtful, reflective, solitary process. Only you can come to understand the complex inner workings of your own mind, and you must be willing to spend the time and effort that gaining such insight requires.