Shaw's observation inverts what we assume is cause-and-effect: we tend to blame aging for our diminished playfulness, when really the reverse is true. The insight cuts deeper than mere sentiment—he's suggesting that the physical act of play, with its demands for imagination and unselfconsciousness, actually sustains our vitality in measurable ways. A grandparent who learns to skateboard with a grandchild isn't just being whimsical; she's literally protecting her neural plasticity and bone density through an activity that requires her mind to remain alert and unburdened by self-consciousness. What makes this different from cheerleading about "staying young at heart" is that Shaw identifies play itself as the mechanism of renewal, not merely a pleasant symptom of it.