I think its quite challenging to pursue this as self-study. Its a longish journey and it requires a lot of stamina and self-discipline. Think of it as pyramid,

I think its quite challenging to pursue this as self-study. Its a longish journey and it requires a lot of stamina and self-discipline. Think of it as pyramid, with ML being your objective to reach the tip of the structure and a number of mathematical topics being the pre-requisite foundations. You need to build them layer by layer, so that the next step is stable and doesn't fall apart in the first difficulty. Listicles are easy to do: multi-dimensional calculus, analytic geometry and linear algebra, fourier analysis, probability and statistics etc. But to understand rather than stochastically parrot these things (the way an LLM would do) you'd need to spend serious time studying and solving problems in each of those areas. The good news is that all of this knowledge is more or less what we call "applied mathematics". It does not require too much mathematical abstraction (which would require even more effort to develop).