Marcus Aurelius spots something most people miss: the dancer rehearses familiar patterns until they become beautiful, but the wrestler never knows exactly what his opponent will do next. Life's difficulty isn't that it demands constant perfection—it's that it demands constant *adaptation*. When you lose your job, or a friend betrays you, or your child takes an unexpected path, you can't simply repeat yesterday's steps more gracefully; you must learn to feel your way in the dark, to shift your weight, to meet new forces with improvisation. That's why the Stoic emperor reminds us that rigidity masquerading as discipline will break us, but flexibility paired with principle holds.