I'm a guy with turbulent emotions. Not unlike girls who undergo mood swings when they have PMS. One thing about me is that my mood is rarely stable. While most people have a constant mood for a certain period of time (if they're happy they will stay happy for like at least one day, if there's no major depressive events), even the slightest cue might make my emotions go haywire. I could be happy all day, feeling all positive and great, and the next thing you know is there's a dark stormy cloud hanging above me just because my friends forgot to ask me for dinner. And the stormy cloud could easily turn into a major hurricane if left unchecked. And then I would be all normal again on the next day after a good night's sleep.
If my Psychology studies were anything to go by (I was reading abnormal psychology just now), I think I would diagnose myself with Cyclothymia disorder. It's something like Bipolar Disorder, where your mood constantly changes from mania to depression, except it's on a milder version and do not impair your social functioning as serious as Bipolar Disorder do.
And I'm not bluffing!
According to what the book says, I fit all the criteria mentioned perfectly. I have alternating mood elevation and depression levels where some days I could feel that I could accomplish anything and the world was a wonderful place while on the others I would be all emo thinking that the world surely hates me. Not only that, these changes in mood are not caused by major events but rather small events that does not affect the normal person. If all these does not point out the fact that I'm cyclothimic, nothing will.
Perhaps this would finally explain how come I could be so emotional and sad some days and how I could be like the happiest-go-lucky person on the others. Seems like this cyclothymia disorder is to blame for causing all these troubles in my life.