There are many different degrees of mental health. No one characteristic by itself can be taken as evidence of good mental health, nor the lack of any one as any evidence of mental illness. And nobody has all the traits of good mental health all the time. One way of describing mental health is to describe mentally healthy people. Just knowing what mental health is doesn't mean you can go out and be mentally healthy, but knowing can help you to think straight about it.
Mental health has to do with everybody's everyday life.
It has to do with the way that each person harmonizes desires, ambitions, abilities, ideals, feelings and conscience in order to meet the demands of life. How you feel about yourself. How you feel about other people. How you are able to meet the demands of life.