Marcus advocates for turning our attention inward rather than outward, focusing on our own behavior rather than monitoring and judging others. This practice eliminates enormous amounts of mental stress - the frustration, anger, and disappointment that come from trying to control or evaluate others' actions. When we redirect this energy toward self-improvement and self-awareness, we not only become better people but also find greater peace. This doesn't mean indifference to others but rather prioritizing our own growth and response over their choices, which are ultimately beyond our control anyway.