Healer: You are Spock, son of Sarek, are you not?
Young Spock: Yes, Healer.
Healer: I have heard of you. I have heard of a tendency toward what humans call "practical jokes."
Young Spock: I did that once, two years ago. Healer, I would not call you out unless a life was in danger. Have you ever heard the son of Sarek was a liar?