one word: Reproduce. It's every species' meaning of life. We are born, we mature, we reproduce, we die, our children mature, our children reproduce, our children die, their children mature, their children reproduce, their children die, etc...
Sad but true.
But the quality of life is a different story. Make your life better by thinking happier thoughts, learn that one hobby you REALLY wanted to learn, and just make yourself happy!
A fight against entropy is maybe a necessary but an insufficient condition to define it as far as I'm aware, but I make a lot of stuff up so w/e. Eventually after the long decay process and the redistribution and breakdown of all your thermodynamically unlikely thingumabobs then it's probably safe to say that it's properly over.