I think it can also be an autism thing too. My SO is on the spectrum, and I'm definitely ADHD but possibly auDHD, and we were both mature for our age. We've always gotten along better with people older than us, especially adults when we were kids.
The biggest trauma I had was my parents getting divorced, but I was always mature for my age.
That's not the American way.
Americans say we're the best at something despite empirical evidence to the contrary.