He had moved the mouse further and further on his desk to the point at which it was ascending the wall behind it This makes me a little doubtful. He would've h

He had moved the mouse further and further on his desk to the point at which it was ascending the wall behind it This makes me a little doubtful. He would've had to pick up the mouse to turn it 90 degrees to move it parallel to the wall, at which point he would've noticed the mouse would move without the pointer moving? In those days, many mouses came with, besides drivers, a somewhat game-like tutorial program that taught people the basics of how to use them.