[Silhouette]

I think part of the problem is that many popular languages now default to using two very different behaviours for elementary tasks like passing variables or parameters around, depending on whether the variable is a "reference type" or a "value type". Simple things like numbers have value semantics. Objects and whatever else works a bit like an object in your language have reference semantics. If you want a reference to a simple value like a number, you box it so the basic type is now wrapped in an object, or something equivalent. Maybe that's even a semi-automatic process that is done for you in some cases. Anyway, that's just how variables work, and the idea that in principle you could have a value of any data type or a reference to any data type doesn't even occur to someone who has learned this way.

Then you get to data structures, and you're trying to explain the fundamental difference between dense, buffer/array-like structures and sparse, graph/pointer-like structures, and there might be no concept of an underlying memory model where the difference is clear.

This has always seemed like a horribly ambiguous and inconsistent mental model to me, and there must surely have been quite a few bugs caused by programmers not clearly understanding the differences between value and reference semantics and exactly when each applies in their chosen language(s). And yet for reasons I can't understand, many of the popular languages today do seem to follow something close to this model.

[narag]

Assembly was fun, but I understand it would be cruel and not so useful to teach it to today students, but I can't figure out how someone can learn some concepts whithout the "memory is an array" model.

My favourite book at college about (the real) data structures started building the array, even if it was already implemented in the language.

[ChrisSD]

I think learning some assembly is essential for any student that wants to use a low level programming language. It's a good way to learn not only about pointers but also the stack, registers, etc. I don't mean they need to be able to manually create a full program in assembly but doing simple exercises can be enlightening on their own.

Of course you also have to mention that even assembly is an abstraction. Memory isn't really a big array, cpus have caches and all that jazz. This matters when writing performant algorithms.

[Silhouette]

It is not necessary to go right down to assembly level to introduce these concepts, though. Just a language with a transparent memory storage model and explicit reference vs value distinction is enough. C is still the lingua franca of the programming world and IMHO it is useful to know basic C for these reasons even if you rarely write much code in it.