That is true, but personally I think about that as coming "after" all the ownership stuff checks out, and as an implementation detail that I can usually ignore.

That is true, but personally I think about that as coming "after" all the ownership stuff checks out, and as an implementation detail that I can usually ignore. I do keep it in the back of my mind though. Btw I have a saying: when you teach, at first you have to lie a little. You paint the broad strokes, then you refine, then refine again, etc. So it's a question of what is a helpful mental model. Knowing the optimization behavior is helpful for some things, but for figuring out valid memory behavior it's useful to pretend you don't know about that.