If everyone lived each day as though it were their last society would break down in a matter of days. This may seem like a harsh indictment of human nature but it's happened before in history - for example in between bouts of the bubonic plague in Europe, many people had lost their entire families to the disease and thought the chance of them avoiding it was unlikely - trade broke down, people didn't produce food, rapes and other violent crime rose dramatically - all as a result of people living like the day like it was their last. The reason the human race has come so far (relative to other species) is precisely because we do NOT live each day like it was the last. It is our foresight, our planning, our hopes and dreams and the desire to bequeath a better planet to each subsequent generation is what makes human life so amazing. It's what separates us from other species. "Live each day like it was your last" is a cloyed, hackneyed phrase and as a philosophy it is detestable.