Misery

Why is it that we crave to feel depressed every once in a while? Have you noticed that sometimes when everything is going just fine, you have that sudden craving to feel bad and wallow in self pity? And you go ahead and do it and make life as blue as possible and make everyone around you feel just the same ( or at least the ones close to you )....
You purposely say things you might not actually mean, but you say it anyway, in the spur of the moment as you want to feel miserable and make the other person feel just as blue as you... Isn't it sadistic to some extent ( a huge extent rather )? I mean, wanting to feel blue is fine.. Go ahead and do it, by all means.. Its your mood after all.... But then ruining the mood of someone else, just so that u may feel slightly more depressed than what you already are.. Is that right?
But you know what? Its fun to some extent.. When you are in that 'low' state, feeling all the more down in the dumps is an amazing experience.. Its kind of similar to feeling high.. When you are high, you just want more and more of it, its almost as if you cant get enough of what you already have.. Its like an obsession..You start plotting ways to do something drastic, you start having these visual fantasies where you're helpless or tied down by something and where you don't tell the other person.. And then you visualise their reaction once they find out and how hurt and upset they will be, and you feel more miserable ( the happy kind of revenge taking miserable )..