Calvin and Hobbes by Bill Watterson for May 15, 1989
Calvin: Good news, Hobbes! I'm starting a secret club, and you can be in it! Hobbes: Oh, boy! Calvin: It'll be great! We'll think of secret names for ourselves, secret codes for our secret correspondence, a secret handshake... We'll have a secret clubhouse with a secret knock to get in, and we'll do big secretive things! Hobbes: Why all the secrecy? Calvin: People pay more attention to you when they think you're up to something.