Great question, Julia. The way I see it: Some people believe that if we do not have our 'revenge', it somehow makes it more likely that other people are going to wrong us again. And depending on the situation, that can actually be true. That's why when we just let something go, some alarm in us just goes off. Some part of us feels that because a person wronged us once, they can do it again: in our brains, they are still associated with the bad thing that they did.

The best thing to do is to simply give it time. Even the worst grudges melt away with time as long as you are actually trying to get rid of them. Good memories remain with us; bad memories we eventually forget.

To say is one thing , to do is another 
 

Some people would give advice to forgive someone who wronged you , neverthless, they cannot take it     once they were also badly treated . So the best policy is trusting your intuition after full consideration . If you do want to forgive this bad guy , I bless you as GOD will help you .Remenber it , to forgive is to release your pressure not just for the wrong guy. If you really did not want to forgive this bad guy , never force yourself to forgive .

The most terrible thing is you were forced to forgive someone while later you utterly regret. 

TO SAY IS ONE THING , TO DO IS ANOTHER 

Forgiveness can be a difficult thing to do...especially if that person has wronged you in a deep and profound way. But it is a good thing to do.

When we are wronged and then remember it later, we can sometimes feel those same hurt feelings. In a sense, it is like being wronged again! I feel that not forgiving someone can eat at your soul and consume your life. If we forgive others, not only can we grow and be happy, we take away the hurt that those memories can cause.

Forgiveness doesn't mean allowing people to keep hurting us...we should do whatever we can to stop that from happening.

One thing that helps with forgiveness is empathy. Sometimes people hurt others because they are hurting. It is hard to do, but if we try to understand how those that hurt us might feel, we can sometimes understand and see what caused them to hurt others.

I know of some good stories of forgiveness that inspire me to forgive. If you like I can share them...just let me know!

But what makes it so hard to let resentment go?  

I believe that in most instances it's because the issue it still "open" and has not come to closure. You can forget and forgive easier if you openly talk about it with the person who wronged you and find out what their motive was. 

Just my 5 cents.

I agree that you should not think every day about the bad people who hurt you, for that only hurts you, not the bad people.

But I do not believe that you  should forgive or forget. I do not forgive the bad people who have hurt me. And I do not forget what they did.  But I do NOT think about it every day.

It makes me happy to think that MAYBE  something bad will happen to those bad people later in their lives.