The text introduces the "Let Them" and "Let Me" theory for managing stress, particularly workplace stress. "Let Them" involves accepting that you cannot control others' actions, such as a boss's decision not to promote you. "Let Me" focuses on regaining control by choosing your response and focusing your energy on what you can control, like seeking new opportunities. The author uses examples, including dealing with inconsiderate dog owners and navigating political frustrations, to illustrate how to apply this approach, emphasising that choosing your response empowers you to manage stress and reclaim your time and energy. The core message is to stop letting others' actions dictate your emotional state and instead, focus on proactive, positive action.