I was taught as many of you were to make my bed every morning. I even "trained" several college roommates to do it and it made a difference in our small dorm rooms.
And like Citruscountyquilter, it emotionally makes me feel better - after my husband and mother died I went for almost a year not making my bed and then one morning it was the first thing I did. When I realized what I was doing, I knew my depression over their deaths was healing and I was feeling better. Since then I have noticed that when I am feeling sick, either emotionally or physically, the bed tends not to be made but when I start to feel better, those sheets and covers get straightened. I call it my own personal "health monitor"!