Happiness is ubiquitous, sadness is sporadic. The issue, however, is the fact that happiness is taken for granted and sadness is attended to. This may be because the nature of true happiness requires to be spontaneous if it is intended to be effective. Yet sadness draws our attention based on  irrelevant intentions to the essence of humanity. The same is true about goodness and badness. I'm a student of applied linguistics, more accurate a language junkie. I have around a hundred books about language, language learning, psychology of language etc. Many of them are written by more than one author. The ratio of female to male writers doesn't seem to be significant. All of them cite numerous other authors, researchers, teachers etc. Thus they outnumber the crew of sadness and badness ship. I can't imagine their families or their lives being just similar to the families or lives shown on TV series. It seems inappropriate if I think the male authors of my books are some alcoholic, drug addict mofos going to bed with a woman every other day, or the female writers of my books are some filthy cheaters having four children each from a different man. It doesn't make sense to believe that these men act the way that my girl friends fantasize. It is ridiculous to agree that these women are the embodiment of the description my boy friends think about.  However, when we refer to examples of everyday life in our everyday lives, we mostly attend to sad and bad examples and forget all the happiness and we had and all the goodness we experienced. When we undergo change, we change under the influence of sadness and badness because we have attended to them.