First, if you smile nicely at peoples, they will know you are nice. Your smile will be like a sunny day, and they will be your Friend.
Second, if you are in the shadows if you are not smiling, they will not see you, and they will not see your face.
Third, if they do not see you after, then it doesn’t matter.
So always smile when they see you, and they will know in their hearts that you are nice.