農人都種地、産粮、吃粮，不是天經地義？除了自然災害，應起码能自給自足。

因此我一直不解造成中国當年長期饑餓的機制.

I didn't experience it myself. I asked my mother (she is now in her 70s), but she was unable to explain it but saying that the government didn't allow the farmers to grow more crops or breeding more food animals. If they did, they would be accused of practicing capitalism. Yet, to me, the government wouldn't want the farmers to starve either. So there must be a better explanation.