夜郎自大 — “To be ignorantly arrogant”

During the Han Dynasty, in the southwest region, there was a small country named Yelang. Although it was an independent country, its territory was very small, its population sparse, and its resources meager. However, because it was the largest among its neighboring areas, the King of Yelang, who had never left his country, believed that the country he ruled was the largest in the world.

One day, while inspecting the country with his subordinates, the King of Yelang pointed forward and asked, "Which country here is the largest?" To please the king, his subordinates replied, "Of course, Yelang is the largest!" As they walked, the king looked up at a high mountain and asked, "Is there any mountain taller than this one in the world?" His subordinates answered, "There is no mountain taller than this one in the world." Later, they came to a river, and the king asked again, "I believe this is the longest river in the world." His subordinates still unanimously replied, "Your Majesty is absolutely right." From then on, the ignorant king became even more convinced that Yelang was the largest country under heaven.

Once, when the Han Dynasty sent envoys to Yelang, they first passed through Yelang's neighboring state, Dian. The King of Dian asked the envoy, "Which is larger, the Han Dynasty or my country?" The envoy was surprised; he never expected this small country to ignorantly compare itself to the Han Dynasty.

What was more unexpected was that when the envoy later arrived in Yelang, the proud and ignorant king, unaware that his country was only about the size of a single Han prefecture, presumptuously asked the envoy, "Which is larger, the Han Dynasty or my country?"