Half empty or half full?

I agree that optimism can be rlly great and it often results in a happier life, in most situation that is. Cause basically being an optimistic nature also gives more positive reactions by others. But in other cases you also have to calculate with the worst case. It can be confusing at first. Or at least i was confused with the whole half empty half full therory. But i realized that if one look at it from a completely different direction. Is it always a bad thing to see the glass as half empty? Not so. Suppose such a perception motivates you to fill the glass whereas seeing it as half full leads to complacency. Focusing on the lack in one's life can sometimes be a driving force for success. 想通了!!!!