Twenty-seven years ago, American teacher Ronald Sakolsky saw a televised story about  a Chinese desert tree-planter Yin Yuzhen and decided to act. He raised $5,000 to help her plant more trees. In return, he received something money could never buy. The experience reshaped not only his own life, but his understanding of China and its people. Today, Ronald has become a household name in China, embraced not only by Yin, but by the millions who followed their story online. Here is their story, in their own words.