Sounds familiar

I was reading The Shahnameh (The Persian Book of Kings). I became intrigued by the story of a man who became the ruler of a powerful and rich nation. He thought he knew better than everyone else on all issues and believed that he could ignore wisdom accumulated over decades, if not centuries. Advisors were afraid to tell him he was wrong. He made foolish decisions and led himself and his country into disaster.
It was said: (He) "is void of knowledge and the sun must revolve yet oft above his head before he learneth the wisdom of the great. For unto true wisdom alone is given to know when to strike and when to tarry. But he is like unto a child who deemeth the world will tremble if it but upraiseth it's sword."