In the 14th century, the eating of mooncakes at "Zhong Qiu Jie" was given a new significance. The story goes that when Zhu Yuan Zhang was plotting to overthrow the Yuan dynasty started by the Mongolians, the rebels hid their messages in the Mid-Autumn mooncakes.Zhong Qiu Jie is hence also a commemoration of the overthrow of the Mongolians by the Han people.
During the Yuan dynasty (A.D.1280-1368) China was ruled by the Mongolian people. Leaders from the preceding Sung dynasty (A.D.960-1280) were unhappy at submitting to foreign rule, and set how to coordinate the rebellion without it being discovered.
The leaders of the rebellion, knowing that the Moon Festival was drawing near, ordered the making of special cakes. Backed into each mooncake was a message with the outline of the attack.
On the night of the Moon Festival, the rebels successfully attacked and overthrew the government. What followed was the establishment of the Ming dynasty (A.D. 1368-1644). Today, moon cakes are eaten to commemorate this event.
It's all about "how much you made when you were right" & "how little you lost when you were wrong"