The Buddhists think we are here to be happy.
I think we are here to know what is called for and to do what needs to be done about it on every level and in every aspect of life and being. We are here to make the word a better place than it was before we arrived. Which is to say everyone makes up their own reasons for being who they are, doing what is theirs to do. Nobody knows for sure. It is the mystery at the heart of existence. What are we doing here? Nobody knows. Everybody thinks they do.