Practicing the dichotomy of control is what Stoicism is best known for, but its operating system has other aces up its sleeve. Another practice it recommends is ‘negative visualization’ — imagining how things could be worse. Allow yourself flickering thought about what it would be like were your biggest fears to come true.
If you assume that what you fear may happen will certainly happen, measure it in your own mind, and estimate the amount of your fear, you will thus understand that what you fear is relatively insignificant, the Stoic predicts.
Negative visualization is a neat psychological trick that lowers levels of expectations and thereby increases your happiness (which, according to my grandma and her cat, equals the sum of reality minus expectations).
In his famous Letters to Lucilius, Seneca many times counsels that we should constrain our desires to increase our delight:
“Riches have shut off many a man from the attainment of wisdom; poverty is unburdened and free from care … Men have endured hunger when their towns were besieged, and what other reward for their endurance did they obtain than that they did not fall under the conqueror’s power? How much greater is the promise of the prize of everlasting liberty, and the assurance that we need fear neither God nor man! Even though we starve, we must reach that goal.”
— Seneca, Letters to Lucilius