A Question That Do Not Require an Answer

I am not a person with a strong memory, according to people that's a weakness, but for me, it is a blessing. With a weak memory, I can easily forget the evil deeds that others did to me. I am grateful, because then the heart will not be easily hurt, injured or else. But the bad effects are I became ignorance, cool and seems don't care of others, it seems cruel, but really it's just my way to keep myself from things that hurt. Sometimes in a marriage, when we no longer listen to each other, we better step back to listen to opinions from other people who are not involved in this conflict. One thing that is sad for me, why two people who once loved each other, now no more listening to each other? Does this signify the love that has faded? Or just a way of life full of tiny sharp stones are quite painful for us to live together? 
It is often said that God hates divorce. But if for the sake of unity in marriage we must accept all the injustices, what about our happiness? Is not the purpose of us getting married is to obtain happiness? If we maintain the marriage for the sake of a family unit, whether the sacrifice is comparable to sell happiness for the sake of an intact marriage. I can not answer this question, can you answer it?