Myshkin's insistence on forgiving everyone who has wronged him in some way is possibly the least comprehensible thing about his behavior, at least as far as everyone else is concerned. Not only does he immediately forgive verbal abuse, deceit, and even violence directed his way, but he then goes out of his way to try to help the people responsible. His compassion in The Idiot overrides any feelings of self-esteem or dignity—but it is also this tendency that makes him the only character in the novel to see Nastasya as anything other than a wasted life.
Over and over again, compassion is shown to be a harmful emotion in the novel. There is absolutely no one the prince encounters who does not try to take advantage of him in some way.
The novel is essentially a conflict between Myshkin, who feels deep compassion for Nastasya, and Nastasya, who cannot feel compassion for herself.