When you increase your self-awareness, you're much more likely to smile because you're more balanced and happy deep inside. Many years ago I encountered a person I hadn't met before at a workplace of mine who looked directly at me and asked why I was smiling. Her facial expression and tone of voice indicated that she wasn't joking, she genuinely wanted to squash my smile and do it quickly.
What happens when you encounter someone who doesn't smile much? What's the feeling you get from them? Countless people live lives of sadness, desperation, and resignation. They're stuck in a depressing place and can't see the positive alternatives available to them. I've found over years of working with people that it's possible to overcome negativity and move in a more joyful direction, but it requires conscious effort and dedication.
It takes a lot of courage to smile, especially in the face of sadness, anger, fear, or uncertainty. The reason I smile in even some of the most difficult situations is because I ask myself, "What's the alternative?" which is, by the way, what I said to the woman.
Building up your self-awareness is like smiling, it reflects your inner light and makes the world a better place. Why do you smile?