Who said "A man who doubts himself has already lost."?

This quote is attributed to Stannis Baratheon.

A man who doubts himself has already lost. - Stannis Baratheon

"A man who doubts himself has already lost."

Stannis Baratheon Courage

"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."

"Never let fear stop you from chasing your dreams."

"Courage is being afraid but doing it anyway."

"Sometimes you gotta do what you gotta do."

"Sometimes you have to be the monster to stop the monsters."