It would be seriously tempting to start gerontifying the big sibs about gray hairs and wrinkles and senior discounts; to start microscrutinizing—-with the gaze of a predator assessing the most vulnerable prey in the herd—-every stumble and moment of fatigue and delay in identifying That Song By That Band as a slippery slope to handing over the car keys and assisted living.

Not advisable, and not the high road, but seriously tempting.