Whether single or taken, plenty of people have a preference when it comes to what side of the bed to sleep on. In any case, it's a smart idea to have nightstands with table lamps or wall sconces on both sides of the bed, so there's a place to stash books, cell phones, and glasses of water. Some of us like to be closer to a door or window when we sleep, which may play a part in our mattress side of choice. For some, the preference is illogical. What side of the bed do you sleep on?