Obviously teenager is 13-19.
“Young adult” would start at 20, but where’s the cutoff at the upper end? Similarly, what’s the range for “adult”, “old”, “elderly”, " ancient"?
If someone asks for responses from “old men”, how do I know if it applies to me?
When nature would have gotten it’s way, I wouldn’t have reached 1 year. I finished my 5th decade, half way trough the 1st century. ;) (my wife ‘celibrated’ her 10y anniversary as cancer patient last year)