A letter from Formosa - Breathing Space Blog
Everyone in class was amazed that the writer did not simply use a piece of fresh paper. My teacher explained that paper was scarce in Formosa and that people used the clear, backsides of any piece of paper they encountered. I had been unaware of the concept of recycling until then.
From that time until today, if everyone, everywhere had employed the backsides of paper and cardboard stock, collectively, humanity would have saved multi-trillions of sheets of paper.