Why is taking the high road so difficult?

Taking the high road generally involves one not expressing their dislike of an action by someone that has wronged them. Humans like closure and justice. Taking the high road does not allow that and instead means the high road taker must accept the wrong and accept no justice and that the closure comes in moving forward, not setting the other person straight on some things, which can be hard when there is an emotional connection to someone such as seen in divorce and child custody arrangements. So, a person who takes the high road will usually not be emotionally connected to the other person, have consciously made it a self policy to do so, or not have the courage to stand up and therefore backs off as they probably due many things in life.