Computers are themselves abstractions upon abstractions. How many levels of cache does a modern computer have? How many memory protection layers exist between y

Computers are themselves abstractions upon abstractions. How many levels of cache does a modern computer have? How many memory protection layers exist between your code and the machine? Hardware keeps getting more complex and it becomes obsolete quickly. It's hard to teach this stuff to beginners because it will probably be useless by the time the get good enough at programming to do anything. Add to that the fact that there are probably 15,000 different platforms all doing the same things in subtly different ways . PS: 'subtly' is a horrible word.