Because aging is a long, stealthy process, a person’s arrival at old age is less a switch thrown than a series of ill-defined thresholds crossed, the transition often first noted by others. Most people over thirty, and certainly those forty and older, will recall the first time “mister” or “lady,” “ma’am” or “sir,” meant them. As our third decade of life cedes to our fourth, aging seems to accelerate. By the time the fifth decade fades into the sixth, the resulting accumulation of physical changes that define adult development transitions from inconsequential to subtly manifest: the crow’s-feet or balding pate and tricky right knee, the friends with cancer, the talk among your peers about ill and dying older relatives. By the ebbing of the sixth decade, if not sooner, the changes are undeniable. Not long after that, they transition to conspicuous, each decade seemingly more profoundly marked than its predecessor. On a daily basis, nothing seems to change, but look back a year or five or ten, and the transformation is pronounced.

Because aging is a long, stealthy process, a person’s arrival at old age is less a switch thrown than a series of ill-defined thresholds crossed, the transition often first noted by others. Most people over thirty, and certainly those forty and older, will recall the first time “mister” or “lady,” “ma’am” or “sir,” meant them. As our third decade of life cedes to our fourth, aging seems to accelerate. By the time the fifth decade fades into the sixth, the resulting accumulation of physical changes that define adult development transitions from inconsequential to subtly manifest: the crow’s-feet or balding pate and tricky right knee, the friends with cancer, the talk among your peers about ill and dying older relatives. By the ebbing of the sixth decade, if not sooner, the changes are undeniable. Not long after that, they transition to conspicuous, each decade seemingly more profoundly marked than its predecessor. On a daily basis, nothing seems to change, but look back a year or five or ten, and the transformation is pronounced.