Suppose that as part of your job/hobby, you do something novel. e.g a new way to configure an internal combustion engine.
Then, congrats you’ve invented something new!!
Unless you’re a mathematician.
In that case, you’re not credited with an invention, but a discovery!
The idea is that math concepts are eternal, they have always been there.
We’re just taking our time to mentally catch up to them and see them.
If this blog about details could have only one article, this would be it!