Ten years ago, the following five propositions were generally believed: that very large amounts of cereals, typically 30-50 per cent, were lost between the harvest and the stomach; that such losses were highest in traditional PHT systems, especially on small farms; that modern PHT could drastically reduce these losses; that such loss reduction was economically cost effective for both farmers and society; that a major reduction in hunger could be achieved by reducing grain losses through modern PHT. In many quarters, this remains the conventional wisdom. Much conventional wisdom is conventional because it is wisdom. But these five propositions seem to be wisdom only because they are conventional. There is now convincing evidence that all five propositions are incorrect.