During the Tang Dynasty, a young scholar named Li Mi, upon hearing that Bao Kai was teaching on Mount Gou, set out to become his disciple. As he rode his ox, he ingeniously hung a copy of the 'Book of Han' on its horn, diligently reading as they journeyed.

It so happened that Yang Su, the Duke of Yue, encountered him on the road. Intrigued by the sight, Yang Su rode his horse alongside Li Mi and inquired about his remarkable diligence. Recognizing the Duke, Li Mi respectfully replied that he was immersed in studying the 'Biography of Xiang Yu.'

From then on, people began to refer to Li Mi as 'Niujiao Shusheng,' the 'Ox-Horn Scholar,' to commend his earnest and tireless pursuit of knowledge.