Wouldn't it be better to keep a pesimistic view on everything?? That way you always expect the worse and when the worst doesn't happen then it's far nicer than the worst happening so you're generally happier...rather than always expecting the best and when it turns out to be worse then you become sad...

You could look at it this way: One person says, "The glass is half empty,"...the second says,"The glass is half full,"...and the third says "Hey!! I ordered a cheeseburger!!".