There often seems to be a playfulness to wise people, as if either their equanimity has as its source this playfulness or the playfulness flows from the equanimity; and they can persuade other people who are in a state of agitation to calm down and manage a smile.
—Edward Hoagland
Humanity has advanced, when it has advanced, not because it has been sober, responsible, and cautious, but because it has been playful, rebellious, and immature.
—Tom Robbins