Once there were two farmers who lived near each other. They had worked the land year after year for most of their life. In time, their crops began to yield less and less.
The one farmer took his extra resources and savings and rented a neighboring field in order to plant more crops to make up for his growing losses. As it was, he was unable to maintain the standard of living to which he had become accustomed. But this field too produced anemic crops and he was no longer able to afford to rent the field. With no extra field, and his money spent, he had to sell his farm and his children lost their inheritance.
The other farmer chose to live with less than that to which he had become accustomed. Not only did he sell his extra car but he decided not to plant on one tenth of his fields. The next year, he planted on the field that had lain fallow and it produced a rich yield. Every year he left a tenth of his fields unplanted and when it had replenished itself and become healthy, the fallow field would produce a better harvest than before. So it was that the fields he had were renewed and gave more fruit and his children took the farm after him.
cf – Walter Russell Mead