because everything else is neccesary.
Sadness: without sadness, happyness is empty.
Fear: without fear, Courage is pointless.
Regret and Guilt: when you fail to act, or act wrongly, these are consequences by which you learn and fuel your desire to do better/differently the next time.
Anger: a potent force of fuel to live by, if you direct and channel it properly. i went through school using my anger as propellant to succeed. why? because i ddint want my anger to be for nothing, do nothing other than loosen my self control.
Shame: this is my most potent and powerful tutor. when i unleashed my anger during my school days, this burned through my arrogance and my anger, this brought me to heel and to reality better than anything else. it is an intensely negative emotion, but it is needed, as the other side of anger.
Hate: Hate may seem strange to keep, but i keep it because without hate, i have no strong boundary preventing me from committing atrocities, my hatred of such weakness, my hatred of loosing control that badly, or acting so wrongly, is what gives me the strength to stand for what i think is right
Desire/Hope: these two emotions are my innocence, forcing its way through me and keeping me from becoming a bitter, cynical prick.
every time i see a pretty girl somewhere, its that wondering sensation of what things could be like, what i would like them to be. admittedly this can lead to melancholy, but usually its provides a pleasant distraction from 'life'
Love: i haven't experience loved properly, having never had a girlfriend or relationship with a girl, but from how i feel for my family and friends, i would not give this up for any price.