It is good that sometimes we experience sadness. Such experience protects us from the illusion that life is all bed of roses. Under trying circumstances, when we feel sad, we are compelled to see reality as it really is rather than sugarcoat it with a pretense of okayness.
I was amazed the first time I heard one of my patients, Carlos, referred to himself as a loser. He felt so sad and dejected. But as I questioned him, I realized he had developed this self-opinion from very few isolated failures. He got locked in self pity.
As Carlos progressed in his therapy, he became aware how much of the narcotic effect of constant happiness and comfort in him came largely from being "overspoiled" and "overprovided" in his family-of-origin.
Carlos was not exposed or shaped enough to understand what life really is like. He got used to life as partying all the time. Everything is expected to be fun and comfortable. So even infrequent or slight discomfort, loss, and failure spelled damage to him already.
Happiness and sadness is the stuff of life. They are twins in the sense that they go together in all lives. Glory and pain always come bound together. Therefore, to see life as it really is, we will have to resist the notion that we ought always to win. Sadness can be a powerful lesson that there is meaning inspite of loss.
At times, our lives are visited by darkness. Failure. Disappointment. Loss. Breakup. Remember then that all is not sadness. There could be an overwhelming happiness waiting on our patience. All temporary sadness or loss can be sustained with meaning in anticipation of a coming happiness or victory.
I agree with my daughter and her poem. Happiness and sadness are twins!