>>13267797one anecdote does not a rule make
I'm in my 30s, I learn programming about the same speed as I did in high school/college
I know more now obviously than I did when programming was newer to me, so its easier to pick up another language. I know a few; all the normal shit like C/java/matlab/lisp/R/ruby/bunch of other randos I've used here and there). I had to pick up python because I required it for some ML stuff that was written in pytorch, and it took me a few weeks to really get the language down. Contrast to java, my second (after basic), which I feel took me nearly a year to pick up in its entirely- but that was because I was both learning Java itself and the structure of programming languages and how they work at the same time.
Most languages are used the exact same way with the exact same features, just some more or less to do under-the-hood (well, once you get past OOP vs. functional, but even then they are doing the same thing, different order).
I imagine learning the same thing over and over again, your brain just gets used to it and has an easier time.