Life has to be lived moment to moment. The past is dead and the future is not born. You can only think and act in the present moment. So decide what you want to do with this precious gift of this moment before it moves on the the next moment. Life cannot be rewound, so there is no use of regret for lost time. The question always is  - What is the best use of my time right now? How can i help myself and others with what I can do? Can i accept what is and take it as the starting point?