It's useless to lecture a human.

“No man may be completely invulnerable.”

“How many other old enemies were in this crowd? Percy began to realize that ever…”

“Hapi?" I asked."Why, yes, I am happy!" Hapi beamed. "I'm always happy because I…”

“Oh, no way," Leo said. "We've been sitting in a cave and you get the luxury ten…”