We are sorrounded with different kinds of people in this world. We have family, friends, special someone and many more. But those relationships with them are not always stable. We committed mistakes that will lead to misunderstanding or the other way around.
Why it is hard to forgive? Some other said that maybe because the trust they gave was broken. Forgiveness is related to trust that everybody should protect. Some reasons maybe they love that person very much but it was just taken for granted.
In my opinion, forgiveness is all we need not because that people deserve forgiveness but because we need peace of mind. Keeping all baggage in our heart like anger will lead to our self destruction. We never wanted to do that. We must overcome those trials by helping ourselves to forgive. Remember that Jesus surrendered his and carried the cross just to forgive all our sins. We people must do the same way. In that perspective all pains, hatred and anger will disappeared.
Still it is our choice wether to forgive or not. But time will heal all of this and you will be grateful.