The amount of people your age is only going down with time.

I see "your age" similar to the dating pool. It grows the older you get. When I was young my brother and his friends were incredibly old. But nowadays they are "my age". I mean, my wife was literally born four days after my brother. That alone increased "my age".
And when I look at the other parents I meet at my kid's schools "my age" is an even bigger group. Add hobbies to that and it's off the chart.
- My first date was terrible. First, my date was hard to reach. Couldn't call her up or anything.. as she had no phone... So we had to talk the old fashioned way... face to face.. and even when I talked to her, she would never reply... like she was giving me the cold shoulder or something... I thought it was because she was shy, and I thought she was sweet at first, but when I reached in the bag, I picked her up and took a bite, I found there was a huge nasty pit in the middle. Then I realized she wasn't a she, "she" was just an ordinary date. From now on, I'm sticking to prunes!
- Oh yeah that's true as well. Like it's more accepted when a 60 year old dates a 50 year old than when a 30 year old dates a 20 year old. It's the same gap, but more frequently seen. That's the thing with cumulative numbers!! The more they go up the smaller the ll% difference in

When you see those Veterans' Day parades and a tiny number of WW2 and Korea vets marching...

Yeah, but today is always the first day of the rest of your life.
- Or the last.
  
  Yeah, but that happens only once per person, whilst the other one happens every day.

What about the amount of single moms in my area?
- That number still remains at zero.
- I know this was the thing online ads always told you, together with “a Russian bride is waiting for you” and all that jazz.
  Do ads still say that by default? As in, when they have zero tracking information?

It can go up on a day where more people one year younger than you have birthdays than people your age have birthdays or die.

People almost always change over time. It’s why divorces happen over “where’s the girl/guy I married”? They don’t exist anymore, they’ve grown and adapted to life around them.

Great news, this isn’t actually true!
Okay, well, the number of people alive the exact same number of years as you is gonna go down. But that number is arbitrary and doesn’t matter.
The thing is as you get older the difference between you and people younger/older than you gets smaller and smaller. You’ve probably noticed that as you get older you can form relationships more easily with people even years older/younger than yourself.
As you get older, more potential friendships and relationships open up to you, until you’re well into old age.

I don't use Facebook but was searching to see if anyone had uploaded a photo I no longer had a copy of from high school. It's only been 20-something years, but the number of obituaries I ran across was surprising. We're all in our early 40s from a small school and the percentage who died seemed high. A couple in war, but medical issues, drugs, and most of all, car crashed.

I had this exact same thought recently and it scared the fuck out of me for some reason. Probably the thought of being forever alone. Then I realized its not that big of a deal but an interesting thought nontheless.
- I'm right here 😊

That seems pretty obvious
What's less obvious is the decrease in population growth. People are having less kids which means that at some point there will be more older people than younger people and that the infrastructure will be overbuilt.
- It does seem obvious, but you kinda don't realise it. Seems like I'm not the only one thinking like that.
  I think in practice, the demographic shift is more noticeable than this.

Debatable, considering that with relativity and all one might age slower, thus pushing into a lower age braked.
Disclaimer a: Great shower thought! Disclaimer b: I am really bad a physics, make me rip if needed.
- I was thinking the same thing, like, "Only because we aren't traveling the stars yet."