Some days, you climb out of bed and everything seems wrong. Your hair is a mess.  You wonder whether you could possibly have gotten older overnight. The news is all depressing. And your family is starting to get under your skin. If it were up to you, you’d just climb back in bed, hide under the covers and wait for tomorrow.What can you do?The first thing you can do is smile. Really. Even if you don’t feel at all happy, you should smile.There are three good reasons to smile in the face of the blues.First, smiling can help surround you with other smiles. Humans are wired to imitate.  When you are in a conversation with someone else, you generally start speaking at the same pitch and speed as the person you are talking to. And when you see someone smile, you will soon find yourself with a smile on your face. So, if you smile yourself, that smile becomes contagious.Second, your facial expression affects how people talk to you. If you walk around with eyes downcast and a scowl, then nobody wants to start a conversation with you. Your whole manner is a big sign saying “Keep Away.” Of course, that solitude will only reinforce your bad mood. The more time you spend with yourself when you’re feeling down, the more time that you will focus on all of the reasons why the world is out to get you. Smiling invites people into your world.MORE: What’s Your Smile Type?Third, smiling actually affects the way you see the world. If you’re like most people, you think of a smile as a reflection of the way you are feeling. When you’re happy, your face breaks into a smile. Obviously, you can force a smile when your brain instructs your muscles to form one on your face.What you may not know is that your body affects your mind as well. Smiling is strongly associated with being happy. Your muscles send signals back to the brain telling the brain what they’re doing. So, your brain knows your smiling. And the information that you’re smiling gives the brain some information to make it think that you’re happy.Not only that, but when you’re smiling, you feel better about the things going on around you. Your friends and family don’t seem quite so bad with a smile on your face. Your hair looks just a little better. Your food tastes a little sweeter.In the end, that smile you plastered on your face just to cover what you were really feeling becomes a sign of how you are actually feeling.Beware, though, it works the other way as well. Putting a frown on your face will make the world seem cold and gray, and will push other people away. Don’t give in to the temptation to revel in your misery.As Louis Armstrong sang: “When you’re smiling, the whole world smiles with you. But when you’re crying, you bring on the rain.”DISCUSS: Has smiling worked for you?