There was a man named Zhang Zai in the Song Dynasty, who once wrote: "Establish a mind for Heaven and Earth, establish a destiny for the people, carry on the lost knowledge of the ancient sages, and create peace for the world for all eternity." He passed the imperial examination and became a Jinshi in the same year as the brothers Su Shi and Su Zhe. When he died at the age of 58, his family was so poor that they couldn't even afford a coffin. It was his students who pooled money to buy one for him. He worked for Heaven and Earth, for the people, for the ancient sages, and for all eternity, but he forgot to save some money for himself. If he was rich, he would help the world; if he was poor, he would take care of himself.