Kids are in love with their own audacity, mesmerized by the world around them, and unstoppable in their pursuit of fun. But in one of the strangest wrinkles of human development, these traits magically evaporate in most people by their twenty-first birthday.
— Steven D. Levitt, Stephen J. Dubner, Think Like a Freak: The Authors of Freakonomics Offer to Retrain Your Brain