I think I was better than most kids at math, particularly algebra, but those kids grew up and caught up and I suspect many of them are as good or better at math than I am. I know nothing about child psychology or anything adjacent, but I honestly think a lot of "advanced child" stuff is just maturity.
ETA:
Should add that this carried on through high school, and since I finished my math two years early, I took college-level courses for math the last two years.
My mom would have none of that, and demanded I be put back in 4th grade.
And so I was, and it was like I wasn't gone for a single day. The class had not advanced at all.
This was quite unlike university, where I didn't dare miss a single lecture.
Agreed university is much harder though.
I was an air force brat, and so attended many diverse public schools.
I took 2 years of honors physics in high school. College freshman physics blew through that in 2 weeks. And then I was in deep doo-doo.
I am eternally grateful to Prof Ricardo Gomez, who kindly took the time to coach me one on one. I never thanked him for that, one of my many regrets.