30 Philosophers, Chapter 13, Marcus Aurelius, Touchstone 34: Negative Visualization.
It is not external events, but our thoughts about them, that cause distress. Many of us don’t truly appreciate our family, friends, and possessions so visualizing their absence increases appreciation for them.
The point is not to dwell on loss, but to use it to better experience the life you have now. Imagine losing a friendship and you may be inspired to nurture it. Imagine a difficult event and you can prepare yourself for it. And by occasionally facing the impermanence of everything you value, you can become more resilient while learning to cherish the present.
Negative visualization finds a modern counterpart in “defensive pessimism,” a cognitive strategy in psychology. You start by casting your gaze ahead, pinpointing potential hiccups in your journey. You then explore those scenarios.