(asuming you have a desktop)
You need a average piece of paper, even a A4 will do. Ply it in two. Cut it with a ruler. Now take that and fold it into two again. Split it with a ruler AGAIN. Write what you want to remember on that piece of paper. Fold it in two 2 times, then turn your keyboard upside-down. Put the folded piece of paper in that little clip thing used to hold your keyboard up, and close the clip up.
Done!