http://people.howstuffworks.com/mad-genius3.htm
"Men have called me mad; but the question is not yet settled, whether madness is or is not the loftiest intelligence -- whether much that is glorious -- whether all that is profound -- does not spring from disease of thought -- from moods of mind exalted at the expense of the general intellect"
The diagnosis of mental illness is such a mess. Probably because ultimately this cruel society just doesn't care so much really about such nuts. The hospital I did clinicals in paid nurses 65% of what they'd make working up the road at a regular hospital for example.
The idea of having mood swings doesn't strike me as so very mentally ill at all. Provided that you aren't hallucinating and still being a productive member of society, I don't think it's a problem at all. But I've seen bipolars who during their mania basically refused to take part in the social norms of this society. Are they ill? Or just different? Are their minds faulty I should say, or just different...
I remember the one guy I worked with, he was euphoric during his mania. And the key was saying to hell with social norms. Obviously he couldn't hold the euphoria all the time. I don't know that there was anything at all in his head working "incorrectly". It didn't seem so.
Being extremely "unfulfilled" could lead someone to grasp wildly in all directions and perform actions that appeared bizarre. And it could lead them to not bother worrying how they appeared to others.