> The first half of the essay seems fairly humble, all things considered, with him saying things like "People always ask if I am a “genius,” but my parents explain that genius is an action ― it requires solving big problems that have a human impact", which I think is great. But the second half seems much more focused on him being very smart and fully capable and just as good as an adult, thank you very much... and I think that's something for his parents to watch out for.

There's a difference between being able to learn something quickly that many people have also learned (though perhaps much more slowly) and having an impact. It sounds like both the author and his parents understand this. The former will eventually help with the latter as long as the latter remains a goal.