Most leaders treat fatigue as an enemy to overcome — but the 10th-century Sufi teacher Al-Muhasibi noticed something more interesting: the moments when our energy runs low are precisely when our habitual masks drop, and we start to see what we actually value versus what we've been performing. He called this the revealing function of exhaustion — not a problem, but a diagnostic. Modern research on ego depletion (Baumeister's original framing, since debated) pointed in a similar direction: under cognitive strain, we revert to defaults. But Al-Muhasibi's version is more useful for leaders, because it's not a warning — it's an invitation. The person you are when you're tired at the end of a hard Tuesday is closer to your actual character than the person you are on a well-rested Monday morning. That gap — between the polished version and the depleted one — is the real territory to develop.

In the last 48 hours, when your energy was lowest, what behavior or attitude showed up that your rested self would prefer to hide?

Drawing from Sufi Islamic Philosophy combined with Moral Psychology — Al-Muhasibi (Kitab al-Ri'aya, c. 9th century CE)