The meaning of life

I think the standard meaning of life is to be happy.

Which is an awfully vague kind of meaning, which in turn, feels like no meaning at all. What is happy? How much of it is enough? What if you don't get it? Does that mean your life becomes meaningless?

So I prefer something like the standard Christian meaning of life - to serve and glory God.
Which for the less religious, would be to serve and glorify life.