At this point even assembly language is an abstraction of a simpler machine overtop of a much more complicated one, and few programmers really understand what's happening underneath. It's not like a chunk of 'memory' in your C program corresponds exactly to a physical location on a DRAM chip anymore. There's N layers in-between, not just in the OS's virtual memory model but also in the chip's caches, etc.

We're all dealing with abstractions over abstractions at this point, so it's really about finding what model of understanding works for the learner and then going from there.