What does it mean that the hidden dragon is in the deep?

"Hidden Dragon in the Deep" means that when there are highs and lows in life, don't get lost in the lows, but always be prepared.

According to China's ancient philosophy, water overflows when it is full, while the moon is full. Everything is ready, except for the east wind, and reaching the peak indicates the beginning of weakness. In other words, it is better to be ready than to show off at the "highest point" of self-righteousness.

Source: From Zhouyi.

Related information:

The Book of Changes, one of the Three Changes of the Book of Changes (another view: the Book of Changes is three changes, not the Book of Changes), is one of the traditional classics. It is said that it was written by Zhou Wenwang Jichang, and its contents include the Book of Changes and the Book of Changes.

Classics are mainly composed of 64 hexagrams and 384 hexagrams, each of which has its own interpretation (hexagrams) for divination. It contains seven languages * * * and ten quatrains explaining hexagrams, which are collectively called "Ten Wings" and are said to have been written by Confucius.