Don't even have to be that old to experience that. There's this weird phenomenon where if you're born at the tail end of the 90s, anyone born 2000 onward feels infinitely younger, even if the actual age difference is only a few years.
I was born 1998 and I still look at anybody born in 2000 like "you've gotta be 12 years old max."
I think that's what happened on Earth Prime and we're in one of those alternate-reality "What if?" comic book Earths. What if the villain known only as Hanging Chad hadn't been stopped?