People always rely on languages and libraries when the most important skill a game programmer need to have is solid fundamentals in math, methodology, troubleshooting, algorithms and optimization.
So how would I be able to learn that? Do I really have to go to Uni and take a Mathematics course? I suppose there's always the internet, but something tells me that it's not going to be sufficient.
Regarding mathematics, if you already know enough of some language and/or game engine you can start be setting the right mindset with talks like that:
And then apply some concepts with channels like that:
https://www.youtube.com/playlist?list=PLW3Zl3wyJwWOpdhYedlD-yCB7WQoHf-MyAlso books about math for developers.
Do not go memorizing formulas or only thinking about numerical results.
Use programming to apply mathematical concepts and increase your possibilities.