I believe in living in the moment. You take action in the present. So that is where you should be living. I live in the moment by paying attention to the things going on around me, being mindful of my thoughts and feelings, and taking action. It is more relaxing and more productive then living in the past or future.
Living in the moment does not mean I do not plan for the future or think about the past sometimes. I make goals and I like to think about past experiences when I want to relax. I also learn from the past. However I don't just wait for things to happen or sit around remembering things that I did in the past. I take action.