No Loss Should Be More Regrettable

Attributed to Zeno of Citium from the Stoic tradition. The irreversibility of lost time — unlike lost money or reputation, which can in principle be recovered — made it the supreme non-renewable resource in Stoic thinking. Seneca devoted one of his most celebrated essays, On the Shortness of Life (De Brevitate Vitae), to an extended development of this argument: most people do not live short lives, they waste long ones. Marcus Aurelius similarly returned repeatedly to the theme that each moment spent in distraction or vice is gone forever.