New answers tagged learning
A data point: I once asked a mathematician who did a PhD in algebra how long he would need to be able to understand the then recent FLT proof by Andrew Wiles. He estimated that he would need about 2 years of preparation. :-)
Terence Tao taught an advanced graduate course at UCLA called Math 285G: Perelman's proof of the Poincare conjecture. So, maybe the answer is that people tend to learn this stuff at the advanced graduate school level.
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