Once time is gone it cannot be recovered. How much time do you waste? I know I spend time on pointless activities and when those moments are used up you can't get them back. I'm not saying don't relax or enjoy social activities with friends or family, but think about the time you have and whether there are moments that could be used in more productive or enjoyable ways.
Geoffrey Chaucer said, "Time and tide wait for no man." They don't stop and they don't wait for you to be ready. So seize the moments in life you have and make the most of them.