What does the old rural saying "cook when you are full" mean?

Beating a chef after a big meal is to burn down the bridge and be ungrateful.

The meaning of kicking down the ladder is easy to understand, and it is explained by an idiom story:

Liu Bei was defeated in Changbanpo. Zhao Yun found his wife and children who were separated from Liu Bei. Cao Cao also chased Zhang Fei to Changban Bridge. He saw Zhang Fei's beard hanging upside down, staring at his round eyes and holding a spear in his hand. Cao Cao was afraid of being cheated and didn't dare to go forward casually. Just then, Zhang Fei gave three roars and immediately scared Xiahou Jie next to Cao Cao to death. It also scared off Cao Cao's millions of soldiers.

Then Zhang Fei ordered to tear down the bridge and chase Liu Bei. After Cao Cao retired, he sent someone to guard Zhang Fei and learned that "Zhang Fei broke down the bridge and left." He ordered his men to build three pontoons and pursue them as soon as possible.

Kick down the bridge by crossing the river: the definition is kick down the bridge by crossing the river, which is a metaphor for driving away people who have helped themselves after achieving their goals.

And said ungrateful. Gou Jian, the King of Yue, is a typical example of ingratitude. A great hero helped Gou Jian, the King of Yue, finally accomplish the revenge of destroying the State of Wu. He is Wenzhong. Without Wenzhong's help, Gou Jian, the King of Yue, would probably die in another country. It can be said that Wen Zhong contributed to Gou Jian's success today. When Gou Jian was besieged in Huiji Mountain, Wenzhong offered to surrender to help Gou Jian survive. When Gou Jian was captured and transferred to the State of Wu, it was Wen Zhong who stayed in the State of Yue and insisted on fighting. When Gou Jian came back from Wu, it was Wen Zhong who put forward seven methods to destroy Wu. According to Wen Zhong's plan, Gou Jian, the King of Yue, defeated the State of Wu after ten years of hardships. However, Gou Jian, the King of Yue, will never tolerate threats to his throne. Wenzhong is a founding hero who is good at strategy. If Wenzhong forms an army, Gou Jian can't beat him. So Gou Jian personally came to Wen Zhong's home to visit him. Gou Jian said, "My brother once taught me to defeat Wu in seven ways. I only used three. What are you going to do with the remaining four? " Wen Zhong said, "I don't see any use." Gou Jian said, "Hum, then you can go to hell to help the ghost king in those four ways." After that, he left a sword for Wenzhong. Wenzhong committed suicide. Gou Jian, the King of Yue, is now a typical example of inspiring people to work hard, but there is such an ungrateful background behind him.

Through the above two idiom stories, we can better understand the meaning of "cooking when you are full". After dinner with the cook, you can beat the cook when you are full, which is a typical ingratitude.