A mouse is a very intimate thing in the computer user's life. You touch it constantly, getting to know it's shape by the most intense sense we have, touch. For hours we push and drag our mice around becoming very aware if their curves, bumps and the way they become an extension of us, temporarily of course. They can be frustrating, they can be uncomfortable, but they are probably the most important link between us and what we want to do with our PC's. When a mouse freaks out or simply stops working, it's like your computer is almost useless. Well, for me anyway. Using my keyboard to function is a handicap for sure, that's why we have backup mice in our house.. just in case.