Mencius was born in Zou (now Zoucheng City, Shandong Province). When his father died at the age of three, Mencius lived with his mother. Meng Mu loves his son very much. In order to find a comfortable study environment for Mencius, he moved three times and finally moved to Gong Xue. Mencius was severely punished for urinating. It is said that he has been studying hard since he moved near Gong Xue. Mencius became very playful when he was a little older. Meng Mu cut linen on the loom. She told Mencius to study hard, or he would become a pile of waste like linen. Mencius kept in mind his mother's teachings and determined to become useful.

When Mencius grew up, he was attracted by Confucius' Confucianism and decided to leave Zou for Confucius' hometown Lu. His teacher was an apprentice of Confucius' grandson Zisi. Through study, Mencius thought that Confucius was the greatest man in the history of mankind, so he was determined to develop Confucius' thought.

Mencius was fascinated by his research and finally became famous. Zou Guo and Lu Guojun often ask him how to govern the country. Unfortunately, it is difficult for a small country like Zou and Lu to realize Mencius' ambition of "benevolent government". He decided to take his students to Qi, a big country in the East. Qi adopted the policy of cultivating elite soldiers, which made the country rich and strong, and ignored Mencius' thoughts. Finally, Mencius came to the knee country, and the prince of the knee country was very interested in Mencius' "benevolent government", so Mencius put his "benevolent government" thought into practice in the knee country. Regrettably, Israel's Knesset is a small country, always in danger of being destroyed, and it is impossible to implement benevolent policies all over the world. Mencius then went to other countries to publicize his "benevolent government" thought. But no monarch is willing to carry out his policies. Mencius gave up the idea of continuing to preach benevolent government and was determined to write a book.