I'm sure some readers are in serious disagreement. I concede that there are some obvious problems with my adjustments to the original idea. I know some people really don't change all that much; I have a friend from my college class that I used to joke was "nineteen going on forty-five". And for the most part, he's been going on forty-five for these past twelve or so years (I guess you'll have to ask me what I think when we turn forty-six).
This friend isn't unique, at least in that respect. 'The Tail End' probably applies better to him than do my above speculations, and on a planet of seven billion I'm sure this is true for many others. Still, I feel people like this are a minority, and that most of us are undergoing some kind of relevant transformation at all times.