Who said "A man's greatest enemy is often himself."?

This quote is attributed to Stannis Baratheon.

A man's greatest enemy is often himself. - Stannis Baratheon

"A man's greatest enemy is often himself."

Stannis Baratheon Philosophy

"Duty is the death of love."

"I am of the night."

"The night is dark and full of terrors."

"A king does not ask, he commands."

"I've seen the worst humanity has to offer."

"Sometimes I wonder if the world is worth saving."

"Every choice shapes our destiny."

"Order is the foundation of a good life."