Answer

In most subjects, I don’t study in order to become an expert, but rather to understand the way of thinking. What I write on these topics does not deal with the details, but with the conceptual framework, and for that a general understanding is enough.
Beyond that, my doctorate in physics obviously helps, because I’m familiar with the mode of thought and the mathematics and scientific logic.
I don’t have any special recommendations, but usually it’s worthwhile to go through university and study something seriously. After that, you can broaden your horizons.