I was so out of it this afternoon at work that I actually moused my cursor up in an attempt to use it to tap the little bobble-headed turtle that sits on top of my monitor. I had entered a state of mind where such a move should have worked. Lucky for me, the cursor reached the top of the screen and went no farther. It did not exit the monitor. I don't know how I would have gotten it back in there if it had. The turtle took no notice.