When people say they hate you for what you are, tell them that it feels better than being loved for what you are not.
No totally honest person can say that they were always happy. Life is made up of happy and sad moments, one cannot exist without the other, just as there cannot be light without dark.
A mistake is not the same as an error. We can make a mistake and correct it but it would ba an error to knowingly make a mistake and do nothing.