All of human history is about the going from sudden fat years to the sudden lean years. We've always had good times and bad, and we've had ways of managing the bad times. We have ways of insulating ourselves, making ourselves less sensitive for the bad times by having things like grain stores, for example. Pretty much every civilization that's lasted for any reasonable length of time has some food management principles behind it. But what's been happening over the past thirty years is it's failed - the insurance policy.