My friend's mom came into the classroom for a parent day shortly after, and I remember my friend asking her to try out this new cool thing.
When he was showing her the mouse and keyboard, she picked up the mouse and rolled the little rubber ball on the underside around with her finger to move the cursor.
We all got a kick out of it at the time. Now that I have young children, I wonder what my moment of "don't really get how this is supposed to work" will be when my kids show me some new technology.