h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Normal doors are the kind of doors that are usually made of wood and have a nob about half way down. These doors can also be very dangerous. Some of them can be sticky, so that when you quickly turn the handle and continue walking, expecting the door to open immedieately, you end up walking into it. Another embarassing aspect of these doors is that some of them tend to be too well oiled so when you swing them shut they make a loud slam, which usually makes you jump and also makes everyone lok at you, either that or you will be asked to be quiet or to stop banging around.