In my late 20s I moved to California and also started playing again after a few years of drought. My strength was about 1950 USCF. In the Bay Area 80% of the players I play in tournaments at that strength are kids -- the median age is perhaps 11.
At first I thought it was shocking that they could be 1950 at 11 years old, and I was like 1200, or whatever. That's a pretty huge gap in what you might think is "talent". But then I started looking at the tournament history of my opponents. I was astonished to find that the majority of them had played substantially more total chess at age 11 than I had managed to play by my late 20s.
For example, here is someone I have played several times:
http://www.uschess.org/msa/MbrDtlMain.php?15250088
He's 10 years old and 2055 USCF. He has played in 175 tournaments in the past 5 and a half years. That's almost three per month, every month! If you don't regularly play in chess tournaments, they are frequently a serious commitment -- the better part of a day, or for big ones, multiple full days. Perhaps his average tournament might involve 10 hours of serious chess. How many adults work so hard on their hobby? Is that degree of return on investment even surprising? I've only played in 129 tournaments since 1992 and I am the same strength.
The player above is not at all an outlier in this regard. I never yet observed a kid who achieved an impressive degree of skill in chess without spending this kind of time. So while I continue to be impressed by the dedication and ability of young kids who are really strong, I stopped thinking that they are magic learning machines whose age makes them unreachably capable. The author's daughter at least has regular coaching, which I suppose the author doesn't have. Does he even spend more time on the game than her? I bet he doesn't.