“Behavioral traits such as curiosity about the world, flexibility of response, and playfulness are common to all young mammals but are rapidly lost with the onset of maturity in all but humans. Humanity has, when it has advanced, not because it was sober, responsible, and cautious, but because it has been playful, and rebellious, and immature.”

“Behavioral traits such as curiosity about the world, flexibility of response, and playfulness are common to all young mammals but are rapidly lost with the onset of maturity in all but humans. Humanity has, when it has advanced, not because it was sober, responsible, and cautious, but because it has been playful, and rebellious, and immature.”

— Tom Robbins