Humans are works of art. And art has been made in many images, the realist, the impressionist and the insane! Such can be useful to define mental health issues...
The healthy are common sense realist. They don't imagine, they just see. They don't envision, they just are. And they think that this is the way things "should" be for everyone. Possibly so, but, probably not. So, the healthy are not prone to bouts of emotional expressiveness, or overly cautious questioning, these people trust life. And they look down on those that struggle, doubt, and question life. They wonder why we don't learn.
The Normally Shaky is most of us. We sometimes don't see clearly and have an over-reactive reaction to some tragedy. We become anxious about the unknown realites that might be, but are not loosing sleep over it. But, sometimes, we do. And we think in terms of "the human", because we understand that sometimes life gives you a curve ball. And we understand that it is normal to need support, care and concern, during those times. These are the impressionist, who see through a glass darkly.
Then, there are those that cannot realize any normalcy, because these have blinders where they can't see any blessings. They focus on the imperfections, and cannot let go of their ideals long enough to recognize that these ideals are walls that keep them from embracing life and accepting others. These are the ones that are never content. They want change. These are the surrealists, who imagine, shake and prod reality for all it is. These are restless souls that have no home. And they find themselves constantly struggling against whatever is precieved to be in their way. Most of the time they are self-destructive because they can't believe that life has anything positive for them.
I think we can move in and out of these categories from time to time and sometimes live in them at stages of our life. But, hopefully, we find ourselves in the stage of impressionism, where life is seen and embraced as not a clean cut experiment or ideal, but a life full of both the tragic and the celebrative! Then we can learn to live with ourselves and others in an understanding way, not demanding, demeaning, or destroying life. Life can be healthy without perfection and THAT is the ideal!