Human emotions are wonderfully complex. There are as many adjectives to describe my range of moods as there are shades of color. Our emotional state of being is a reflection of our present circumstance, the factors that brought us there, and our reaction to it all.
When a tragedy occurs, it's healthy to react in a way that's emotionally appropriate. If there is a death of a loved one, one is expected to be in mourning. It would be considered out of the ordinary if one rejoiced instead.
Every negative emotion is part of the healing process. It's exactly what people need to go through in order to get to a state of happy. Ignoring these emotions eats away at our souls. Bottling it up inside creates a tumor that threatens our happiness.
Happiness is beautiful, but without other emotions, how would we ever know what happiness truly is?