Happiness is in fact a mean used by nature to handle us, lead us to satisfy its goals, survival and proliferation of species.
It is important to be conscious of that to be really free. Those who are not conscious of that are puppets handled by nature.
Survival for survival, without other goal, seems to me a futile goal, and I keep hope in the existence of another higher goal for which I am steel searching.
The hypothesis of mathematical universes also brings a new viewpoint about this question.
The existence of the universe would simply come from a metaphysical (or metamathematical ?) law according to which any infinite mathematical theory would generate a universe inhabited by spirit.
We could consider that only mathematics would exist, that physics would be a branch of mathematics.
There would be no goal, no reason of being of man in the universe, but we would be free to chose the goal that we want.
The goal would consist to refine the laws of physics by our actions, to build in appearence, explore in reality, the universe that we want.
It would be a mathematical exploration in which personal criters, esthetic for example, could be used. This would be a sort of self exploring.