Yamamoto Tsunetomo. Hagakure (№ 123561)

A warrior should be careful in their actions and to avoid even minor mistakes. Moreover, it needs to be careful in the choice of words and never say, "I'm scared", "In your place I would run away", "This is terrible!", or "How painful!". These words should not be spoken in no friendly conversation or even during sleep. After all, if a shrewd man hears from other such statements, he sees right through him. Your speech must follow.