This world of duality cannot, by its very nature, give us permanent happiness. The good and the bad are the two faces of the same coin. We cannot have one without the other.
However, that does not mean that we cannot be happy. We can. It is our nature.
However, we can only be truly happy when we see clearly, when we stop hoping for things to be different from what and how they are.
Everything that happens, the good and the bad, is beneficial. Perhaps not in the way we have expected, but every experience gives us the opportunity to see reality as it is. We can learn to see clearly.
As long as we expect others and external situations to make us happy, we will be frustrated. However, when we realize that our happiness is not dependent on anything or anyone external, we are happy.
When we renounce the illusion of duality, we abide in peace, and that peace is the reality of our own true purity, true being, true bliss, and true permanence.