When you hit a certain age, a number of activities you once engaged in as a youth start to cause you physical pain. Activities like running, yardwork, household chores, sitting down, standing up too fast, and sleeping. 

Yes, sleeping. In fact, the sleeping thing might be the most insulting. All you want is a few hours of silent slumber to recuperate from that muscle you pulled while tangling with a fitted sheet, and the sleep itself is causing harm. Your back hurts. Your hips hurt. Your n...