Knowing that a particular interface is almost completely accidental is often the key missing piece in going from being utterly helpless to solve a problem to being able to puzzle it out.
Yes! A lot of interfaces are largely arbitrary fictions! If more people understood this, there would also be fewer fan boyish arguments.
Also suggests a metric/strategy: minimize the amount of fiction in your UI and maximize the fundamental principles. (Example, sliders are well understood, because most people understand basic geometry.)