It's the age of no memory
The Chinese idiom, MI ǎ nhu á izh ī Su ì, means three years old. It comes from the Analects of Confucius Yang Huo.
The origin of Idioms
In the Analects of Confucius, Yang Huo: "the son was born for three years, and then he was free from his parents."
Idiom usage
As an object; in writing
It's the age of no memory
Be lenient if you are in a hurry - jí chù cóng kuān
the iron tree in blossom -- sth. seldom seen or hardly possible - tiě shù kāi huā
entice one 's opponents to leave their vantage ground - diào hǔ lí shān