I see a flaw in this logic. One certain bad thing that will happen to you if you leave every day as if it is your last is that you'll end up being > 200 kg (would you go to the gym the last day of your life? Would you resist the urge to eat as much as you like?). Another is that you will stop learning anything (would you go to your french course in your last day?) Another is that you might become a drug addict (some people might decide to see how crack feels like in their last day, something they wouldn't do otherwise). Another is ... ok, I believe you get the point.