When I first read this as a teenager I didn't see what the big shocking secret was supposed to be, after all very above average people appearing to be significantly better than the average seems like a tautology.

And then, as I grew up, I realized many folks don't like admitting that someone else could be better in a general sense, maybe out of stubborn pride, or mistaken beliefs in literal equality of outcomes. Or maybe because they're afraid of putting in the effort to improve themselves, preferring the easy way out as a crab in the bucket.

In any case, it made me reflect on how many other 'obvious things that cannot be said' appear everywhere as one grows older.