A year to live and nothing to lose

What would you do if you found out you only had a year to live? Why do we wait until the end is near to take shit serious? 

We take life and everything in it for granted. We have no idea if we have an hour, a day, a week, a month, a year or 20 left. We all assume we will live for ever. We live our lives under the assumption that there will be time later. I'll take care of it next week, we always say. What if next week never comes? Why not right now, or today?