I heard you, somebody just said life is not always happiness and smiles; no it is not. Life is not intended to be happiness and smiles every single moment of your life. However, the happiness and smiles are what makes your life worth living. Happiness and smiles are what just brings you peacefulness, joy, harmony.
Sometimes the contrast or the lack of happiness and joy in your life allows you to appreciate it, even more, when it comes back. These things may cyclically, cycle; they move in a spiral through your life so that sometimes they are there and sometimes they are more distant.