Sad are only those who understand
Every man has his secret sorrows which the world knows not; and often times we call a man cold when he is only sad. The walls we build around us to keep sadness out also keeps out the joy. Nobody deserves your tears, but whoever deserves them will not make you cry. Sadness is always the legacy of the past; regrets are pains of the memory. Smile, even if it's a sad smile, because sadder than a sad smile is the sadness of not knowing how to smile.
Bad things do happen; how I respond to them defines my character and the quality of my life. I can choose to sit in perpetual sadness, immobilized by the gravity of my loss, or I can choose to rise from the pain and treasure the most precious gift I have - life itself. Even a happy life cannot be without a measure of darkness, and the word happy would lose its meaning if it were not balanced by sadness. It is far better take things as they come along with patience and equanimity. Grief and sadness knits two hearts in closer bonds than happiness ever can; and common sufferings are far stronger than common joys. I do believe that if you haven't learnt about sadness, you cannot appreciate happiness.