When a situation arrives do you see the good in it or the bad, are you one who sees the glass half full or half empty?
I think if we can go throughout our lives seeing the good in things we will be happier, yes I know it isn't always easy and there are some things that really there is no good in but over all if we try to see the good in things we will be happier.
Seeing the negative, encases us in cloud of negativity and that makes us sad, and when we are sad we can't see the positive so it is a vicious circle and too many people find them selves trapped in said circle.
I feel there are times when we have to take a deep breathe and centre ourselves and look for the good. It may not be easy but it will be worth it, in the long run.