When faced with any of these discomforts, Marcus would simply warn himself, “You are giving way to pain.”14 Then he’d apply the same coping skills, whether he was struggling in a blizzard along the Danube or suffering fatigue from riding for days from his base at Aquileia in northern Italy to the legionary fortress of Carnuntum. Pain, discomfort, fatigue—they’re all just unpleasant sensations.

