I happen to be a math professor (it’s weird that so many topics in this thread are touching on my personal experiences but I promise I’m telling the truth!), but for several personal reasons, I wasn’t a top student.
In my experience on both sides of the lectern, there are two kinds of students: the ones who coast on natural talent and the ones who work for that A. Natural talent always runs out eventually, and it often wrecks students who’ve never had to build coping skills. That’s exactly what happened to me! The only reason I went the distance and got that degree is that I transformed myself from the former student into the latter student.
I know this sounds discouraging, but I think it’s reassuring. There’s no need to be born special. It might take longer, but just about anyone can be that good at Japanese (or math) someday. You just need discipline and willpower!
EDIT: In other words, I don’t think it’s important who the best is or how long it took them. Whether that person’s results were faked changes nothing about what you should do for yourself. If you keep working and growing, you could still surpass them someday. But what’s much more important is that you could find the satisfaction within yourself that you know you’ve acquired a useful skill.