What we seeks most often in life: pleasure, joy .. happiness! ;) Through our actions we try to create a situation in which we hope we will feel good. Actions and situations often among those that have already given us a form of « pleasure » in the past. This is the most common behavior. It is rare to hear someone openly declare that he is trying to feel bad … Why would we want this? That would be incomprehensible?
Well, no, not that much when we know the intimate functioning of our sensations, indeed, after having « suffered » we will « logically » feel a form of well-being, resulting from the « re-balancing » quite simply. Since the two groups of sensations literally « feed » each other, when the imbalance becomes too great, a re-balancing in favor of the other group is inevitable (and it also works in the other direction: After a series of intense joy one may find oneself « constrained » to anger, violence or anxiety according to your « usual » mode of operation.)
If the suffering occurs in a sufficiently rapid and intense way, the « re-balancing » can even occur in a brutal way during the session of « torture », in « rush », it is called « masochistic ecstasy » (wiki link in French, did not find the corresponding English one)
Masochism thus becomes an action in order to feel good, but a little upside down, beginning with « pain« , by « creating an important imbalance ». One can have seen the effect of this behavior empirically : « I suffer, but it causes some sort of bursts of pleasure and in any case « after » I feel good… ». (Precision: I’m not like that, but since I’ve been aware for a while of how the sensations work I quite understand the principle obviously)
Feeling bad is a very strong taboo in society, it seems to be even a reason for exclusion. Understandably, the moods are very « communicative », there is the « emotional contagion », in both directions… Then we have a sort of « obligation » to give the impression of feeling good ! (This is the biggest « obligation » in society I think, but again it is « understandable ».) People who practice masochism by accepting to feel bad (even very bad) in a first time, not only « re-balance » their level of « joy« / »sorrow » if they were in « imbalance » of « sorrow » before but in addition they probably « get ahead ». But it requires to accept to suffer a lot, which is not so easy I guess…