It is tempting to think that a mathematical proof alone can 'create' a truth about the markets, but that ignores human complexity. Imagine the scene: a regulator, a central bank, facing economic turbulence, where human actors do not always follow pure equations. The equivalence of sensitivities between fixed points and KKT conditions, although theoretically demonstrated, can be undermined by political decisions or changes in behavior. An unexpected turn in the fiscal policy of a eurozone member state, for example, would alter incentives and make this equivalence more of an aspiration than a reality. Models are only guides; true value creation depends on enlightened human intervention.