On the other hand it's literally never been easier. Seriously, don't so much spend the time learning a discipline as learning to learn with any of the free online LLM tools for any subject and if you've actually got the gumption you'll go far. The 2nd qualification in life is often the toughest but the 3rd and 4th are often the easiest.

I'm partial to MathAcademy for learning math as an adult learner. Not cheap but so so so worth it.