When you're a writer, one of the effects on your life is that you're always processing the events around you on two levels: Your gut reactions, and your writer's eye for the bigger story.
For some writers, this metacognition brings misery. Think of all the tortured artists throughout history, whose sensitivity made the experience of life painful (e.g. Goethe).
But for me, being a writer actually makes me happier. Writing improves my mood and fills me with energy. And I think I know the reason.
As I process the events around me and the information I read, I use them as the raw materials to craft a positive story. Setbacks become learning opportunities, and triumphs help give meaning to an overall life narrative.
Rather than life seeming like one damn thing after another, life becomes a story that I write with both thought and deed. And in doing so, I feel a much grater sense of control over its narrative.
If you want to be happy, always be crafting.