Life is a combination of good and bad times. At times we are happy and at another point we are not as happy. This is because we affiliate certian things as our landmarks for happiness and sadness. If that landmark is reached by a stroke of gud or bad luck, we go in a state of happiness/ sadness. I suggest that we should set these landmarks/ threshholds as per nature of our personality. For happiness our threshold should be minimum and for sadness it should be maximum.