You're saying they don't use math textbooks and math forums to train LLMs, then?

The problems are not in textbooks. I’m curious what would count as an out of distribution problem for you. Only problems no one knows how to solve?

You can apply this same argument to humans, 99.999% of people will not be able to escape it.

In the case of the Math Olympiad, the students who take it grind hours a day for months on practice problems and past Olympiad problems.