Your mind will continue to produce thought just as your heart will continue to beat. If you want peace of mind, it is not about the thoughts alone, but rather your attachment to those thoughts. I guess what I’m trying to say is this: learn to let go. Do not dwell on circumstances outside of yourself, but instead meditate on the health of your body and spirit. Because thoughts turn into words, and words turn into actions, and actions define your character, and your character determines your destiny.