Mencius was born in the state of Tsou during the Warring States period (475--221 B.C.). When he was very small, he and his mother moved next door to a graveyard, and he and the neighboring children would play at funeral rites.
Seeing this, Mencius' mother thought, "The boy mustn't be allowed to stay here." So she moved into the city.
In the city Mencius and the neighborhood children played at business and trade. Making misrepresentations and exaggerated claims, they mimicked salesmen doing business with customers to a tee.
"This will never do," his mother thought. "We'll have to move again."
The third time, she moved next to a school.
There things were different; now Mencius learned etiquette and manners. He and the other children played at being orderly and polite.
"Now this is the right kind of place for my boy," his mother said to herself.
In order to find her son a better living environment, Mencius' mother moved to three different locations. The expression "Mencius' mother moved house three times" was later used to describe a mother who always strives to do the best for her children.