>>12482917I remember reading about a mathematician (Hardy, I think) discussing some difficult proof of a theorem in number theory and saying that according to him no elementary proof of such a theorem would be possible because some theorems are simply "deeper" than others and can't be reached without considerable machinery, and if an elementary proof of such a theorem is ever found then everything he thinks he knows about the structure of mathematics may be wrong. And guess what? An elementary proof of that theorem has since been found.
>source: my assI don't remember where I read about this, so take it with a grain of salt.