Medieval knighthood hinged on the opportunity cost of decades of full-time training

Evidence

The biggest and best human weapons have always been exorbitantly pricey, unattainable to all but the richest few. During the Middle Ages, for example, the cost of a knight’s armory was extraordinary. The biggest cost of all was the opportunity cost. A knight had to be wealthy enough to never have to work. From the time a potential knight became a teenager, training to fight was a full-time occupation, often spanning a dozen or more years. The freedom to pursue this path simply wasn’t available to the overwhelming majority of young men in Europe at the time, since they were indebted tenants of local lords. Even among the aristocracy who could swing it, not all apprenticeships were equal: some could afford to train with better masters than others. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 345

Categorization

• XREF: The opportunity-cost framing echoes the mandatory-vs-discretionary resource pool logic for animal weapons in the same chapter.