“As the late neurologist Max Levin theorized: "If play were not pleasurable, kittens would never chase each other's tails, and so would lack practice in the motor skills needed for survival. If there were no pleasure in the appreciation of the absurd, if there were no fun in playing with ideas, putting them together in various combinations and seeing what makes sense or nonsense -- in brief, if there were not such a thing as humor -- children would lack practice in the art of thinking, the most complex and most powerful survival tool of all.”