Packing stress is a common psychological phenomenon rooted in the fear of the unknown and the pressure of "decision fatigue." When you pack, your brain is essentially forced to simulate every possible scenario of your future trip—from weather changes to social events—and decide which limited resources will solve those potential problems. This creates a high-stakes "what-if" loop that can trigger the brain's fight-or-flight response. Additionally, for many, a holiday represents a significant financial and emotional investment, leading to "tragedy dress rehearsals" where you worry that forgetting a single item (like a specific charger or medication) will ruin the entire experience. To mitigate this, psychologists recommend using a standardized checklist and starting the process a few days early to break the decisions into smaller, more manageable tasks, thereby reducing the "last-minute" cortisol spike that causes that familiar feeling of panic.