When I was young, I knew that the world was difficult, and the Central Plains looked like a mountain in the north. (Lu You)

It used to be difficult to cross the sea, forever amber. (Yuan Zhen)

Once the sea was difficult for water, forever amber. (Yuan Zhen)

Know yourself and know yourself, and you will win every battle. (Sun Tzu's Art of War)

Knowledge is power. (Bacon)

Even a wise man may sometimes lose. A fool may give a wise man counsel. (Yan Zi Chunqiu)