That's a rough approximation of my beliefs. The universe is massive and long-lived. I am neither.
I want to leave the world a better place than when I entered it. That trickles down to my daily life - are things better or worse when I go to bed than when I awoke? Being as insignificant as a rock doesn't preclude that desire.
And frankly, it's kind of offensive when Christians tell me I'm less-than-moral because I don't need their scripture to decide what's good or bad.