The initial reason why I decided to study mathematics was that I had difficulties reading ML/AI scientific research papers on https://arxiv.org/ This was a bit odd because in school I had a particular focus on math and science.
While reflecting more about the idea and understanding better the difference between school math and university mathematics I realized that math might also help joining my thinking skills. Real life is often very messy and I observed that most of the time thinking is being replaced by searching in google for a good enough solution to solve the problem.
In the past I was a big fan of learning foreign languages but language is in practice almost exclusively a matter of memorizing, not thinking. Philosophy would also be a good candidate for honing thinking skills but after reading a few books i was a bit disappointed by the gap between the texts and realities of real life. The abstract nature of math, the cleanliness and purity on one side and its applicability in my job on the other side makes it attractive.