We live at the behest of ourselves in order to learn the True lessons of life. Among these teachings are that you never hurt anyone including those that seem to aggravate you the most.
If a person aggravates you - you can bet they are getting a bit close to home and you must listen to the lesson. Those that aggravate the most have many of the qualities that you have that you wish you could abolish.
Those who hold grudges or use them to further their own agenda's are the Sacred Evil in our world! When challenged by Sacred Evil one must not give in to the temptation of retribution but instead think and do kind deeds for these vendors of terror! Through your unselfish acts of Love and compassion they will become less Evil and even begin to change for the greater good according to Creators laws.
If you cannot forgive a persons unkind words or deeds you become exactly the pain and suffering that you believe they have inflicted upon you. You will then live to re-experience the unkindness and the hurt that you believe has been done to you. To overcome these issues you do exactly the opposite that your fight or flight response is prompting you to do. You face the issue, you experience the issue, you hold it to your heart and you overcome it, not run away from it.
Aho - Two Feathers