Happiness is

I wouldn’t want to be in a world without any suffering, because then there would be no compassion and understanding either. If you haven’t suffered hunger, you can’t appreciate having something to eat. If you haven’t gone through a war, you don’t know the value of peace. That is why we should not try to run away from one unpleasant thing after another. Holding our suffering, looking deeply into it, and transforming it into compassion, we find a way to happiness.
With mindfulness, the feelings that have been painful and difficult transform into something beautiful: the wondrous, healing balm of understanding and compassion.
—  No Mud, No Lotus by Thich Nhat Hahn