How to keep smiling?
What robs you of your smile is unpleasant events. Events that do not bring comfort or which appear to give you misery.
When you realize that you are much bigger than events that occur, then the smile on your face will not vanish.
Second when you know that there is someone to guide you, take care of you, then also your smile will not vanish.
Third when you know that you are here to give. That gives you strength to move through moments when you cannot smile.
Sri Sri Ravi Shankar