Not every sky will be blue and not every day is springtime. So on the spiritual path a person learns to find this kind of happiness without needing nice things to happen on the outside. Rather, you find happiness by being who you really are. This isn't mystical. Young children are happy being who they are. The trick is to regain such a state when you are grown and have seen the light and dark sides of life.
The ultimate goal of all goals is to be happy. If you want to be happy make someone else happy.
The purpose of life is the expansion of happiness.
Happiness is a continuation of happenings which are not resisted.