Synchronization is like a sub-problem of working with concurrency. In this context they’re the same afaics CPU reordering isn’t hard to understand, itself, bu

Synchronization is like a sub-problem of working with concurrency. In this context they’re the same afaics CPU reordering isn’t hard to understand, itself, but building systems that depend on it is (like building a time sharing OS… very difficult) because it’s difficult to reason about. The implications of it are hard to understand because, as you say, we’re not naturally apt at multitasking