Calvin and Hobbes by Bill Watterson for April 05, 1991
Calvin: You know what I've noticed, Hobbes? Things don't bug you if you don't think about them. So from now on, I simply won't think about anything I don't like, and I'll be happy all the time! Hobbes: Don't you think that's a pretty silly and irresponsable way to live? Calvin: What a pretty afternoon.