When I read this quote, I couldn't help but think how very profound this statement was. Marriage is not always a bed full of roses. You've heard it said that marriage is 50/50... well, it's not... it's 100/100. And usually it's more of you giving 100% and the other one doing a lot of taking. This being the reality of marriage, then the first lesson you need to learn is that of forgiveness. You will never have a happy marraige if you hold a grudge or allow your feeling to remain hurt. Your feelings will get hurt (many times) even though that spouse loves you dearly. We are all human and sometimes we say and do things that we shouldn't or that we don't really mean at the time. Again, this is why you must learn the importance of forgiving your spouse. If you don't, you only hurt yourself more in the long run and make matters worse instead of better.
Another lesson that has to be learned about forgiveness is this... don't wait for the other one to come to you and ask for forgiveness- you may find yourself waiting a LONG time. Often, we aren't even aware that we have done something to hurt or cause grief to our spouse. You must learn to initiate the forgiveness and take the first step even if they don't.
The best advise that we can give to each other in the marriage relationship is from the scriptures... "Let not the sun go down on your wrath." (Ephesians 4:26) In our modern day language it means- "Don't stay angry, don't go to bed angry." (The Message) Anger not dealt with will keep growing until it gets bigger and bigger and too big to handle. Unforgiveness is the same way... it just keeps growing and before long you have a whole set of problems including some that weren't there in the beginning.
As our quote above says, "a happy marriage is the union of two good forgivers. Forgiveness must rule and reign in your marriage. Forgiveness is a sign of true love... "Love doesn't keep a record of sins that were done." (1 Corinthians 13:5)
If you want a happy marriage, if you want to stay happy in your marriage... learn to forgive.