When I was a little kid, I was playing in my dad's office while he was in a meeting and was drawing dinosaurs on his dry-erase bord. Unfortunately, I was using permanent marker and I got so scared I would get in trouble, I cried. His secretary heard the commotion and was nice enough to show me that if you draw over the lines with a dry erase marker it'll all come off when you erase it. She was also nice enough to take me to the bakery across the street and get me a cookie.