I'd also disagree that most people have names that identify their age.
And you probably wouldn't be wrong, but you're looking at it the wrong way around.
It isn't that people necessarily (all) have names that date them - it's that there are certain names that can, 9 times out of 10, date the owner to a generation.
If I meet a Sharon, she's probably (not definitely!) going to be 40-50-ish.
If I meet a Simon, Nicholas, Mark, Jeremy, Dave, Kevin or Richard - he's probably not going to be 5, he's probably going to be my age.
If I meet a Tony, Brian, Trevor, Derek, Ronald, Kenneth, Michael, Gary, Barry, Douglas, Bruce, he's probably going to be one of my Dad's cronies.
Babies aren't being called those names much any more, right??
Karen, Nicole/a, Angela, Jennifer, Stephanie, Joanne, Shelley, Rachel - my era.
Helen, Marion, Mary, Beverley, Pamela, Annette, Ann/e, Janice, Janet, Hilary, Patricia, Joan, Maureen, June - my Mum's era.
Feel free to say you can't see it, but it's blindingly obvious to most people.
And I say this as someone who was given a name so embarrassingly 'old lady' in the 70s that my parents wondered if they'd made a terrible mistake. I used to get teased about it all the time. I've never met another person my age with the name.
It - and all its accepted variations - is now top 10, and so popular, you can't move for young girls with the name.
I was just given it out of synch with the zeitgeist, so I'm probably more aware of this phenomenon than most.