Nothing demystifies 3D graphics more than learning the relevant rudimentary parts of linear algebra.

Casey Muratori's Handmade Hero series has several excellent explainers aimed at aspiring game developers, there's even a math playlist:

https://www.youtube.com/playlist?list=PLEMXAbCVnmY7lyKDlQbdb...

Learning that perspective happens via /z is nowhere near sufficiently demystifying IMO