The best way to understand how a modern computer system works is to learn the ASM of that language, read the manuals for the CPU/motherboard. You need to learn about registers, memory addresses, L1 and L2 caches, interrupts, etc. I don't see how C forces you to learn about any of that aside from memory addresses which you don't really need to deal with much (aside from passing pointers around and using malloc/dealloc).