I remember a related discussion in John Holt's "Teach Your Own," about why children sometimes have a hard time learning right and left. He noted that left and right are often defined differently depending on what you might do with the object you're describing. "The coat's left pocket" means the pocket that would be on the left if you were wearing the coat, and "the desk's left-hand drawer" literally means the drawer I'd put my hand in if I were sitting at the desk. This requires the child to imagine a hypothetical situation. But "the monitor's left side" means the side closest to my left hand, because I'm facing it, and never anticipate getting behind it to face the world from its point of view. No wonder kids find this confusing!