My mother got knee surgery on her left knee fairly recently. When she got home, over her left knee, in black sharpie, was written the word "yes." Over the right knee was the word "no." It frightened me that doctors could screw up so badly that they would write the words yes and no on somebody's knees. It frightened me then. Now it gives me a nice feeling of reassurance. If I ever need to have surgery, I will make sure to write the word "no" everywhere on my body except for where they are really supposed to operate.