Almost all the really successful people I have known were self taught.
In an interview on C-Span, Mark Steyn (probably the western world's greatest writer) answered a caller that he had learned all he needed by the 8th grade.
I did my graduate work in organic chemistry. I made my fortune designing microcomputer software and hardware (100% self taught).
With the world's greatest access to information and training at your fingertips (Internet) you can become expert in anything you wish. You used to require access to university libraries to do this)
If one observes the world around themselves, they might notice that there are people in the world with varying degrees of intelligence.
For instance Steven Hawking. But then you need to look at the other end of the spectrum as well (Such as Downe's Syndrome children)because all levels exist, and they always will. There used to be a Bell Curve and it was used by educators as a useful tool until the PC crowd declared everyone has the same IQ. It is not a matter of our choosing where we will fall on that scale. I will concede that IQ level can increase, but only slightly with education.
The next obvious step imposed by Hitler. Eugenics, that way either you came up to his standard, or you were disposed of. Far better that we realize that not everyone has the same potential, and deal with that truth.
For those who think they qualify here is the standard....
Genius IQ is set at 175. So if you score 175 or higher on an official IQ test, congratulations you are a genius with a certified genius level IQ! You are one in a million! You join the ranks of such luminaries as Bobby Fischer, the chess champion (187). If you scored an IQ level of 195, then you'd be one in several billion, just like Long Island bouncer Chris Langan, who not only flexes a muscular 250lb physique but a muscular mind that notches up a certified genius level IQ of over 195!