A pet peeve of mine in this regard is about throwing away food that is left on a plate. Many people feel a moral duty (often instilled in them from a young age)

A pet peeve of mine in this regard is about throwing away food that is left on a plate. Many people feel a moral duty (often instilled in them from a young age) to eat everything that is on a plate, even if eating that last 10% would make them feel uncomfortable for an hour and would have no utility from a dietary point of view (actually have negative utility, since it only increases their fat intake). Yet I have a hard time convincing people of this, and some people sometimes feel the need to scold me for throwing away food. Despite that, I've been better off since I internalized the true nature of this (daily recurring) situation.