To be honest, and I speak from experience, to forgive AND forget as it's typically understood isn't always the best course of action. Well, again, the forgiving part is wonderful for you in particular but the forgetting part can't be done. I'll give you a silly hypothetical example to illustrate my thought process. I stuck my hand in the fire and it was horribly burned. I was angry at the fire but decided I did not like how the anger felt along with my burns. So, I allowed the burns to heal and the anger at the fire to dissipate. I forgave the fire for burning me. I forgave myself for sticking my hand in the fire. Now, forgiveness is absolutely divine in this example. However, I would be terribly unwise to forget that fire is hot and that the last time I stuck my hand in the fire, I was horribly burned.
Extrapolate this concept across to any given situation. The idea is to forgive the other person who seemingly wronged you, forgive yourself fully for making a choice that resulted in you being wronged and then let go of all anger, frustration and negative energy created by whatever it was that required your forgiveness. Carrying a grudge is very harmful to you energetically, emotionally and sometimes even physically and please don't get me started on vegeance. Let go of the grudge and negative energy when you forgive. If you do not wish to face the same anger and frustration, you will have to remember what you learned of the situation without having to relive the anger and frustration or consciously consent to it's repeat. Forget the negative energy and animosity of the situation. Forgiving and forgetting does not mean you are obligated to put yourself back in harm's way to do the "right thing" with forgiveness and forgetting. We were blessed with memory for a reason. Use it wisely to guide your decisions in the present. Do forgive and forgive fully but do NOT forget the lesson you learned.
There are many additional examples in this world that will be obvious to you in demonstrating that forgiveness is good but forgetting may be a bad idea (check your local city police blotter if you want more ideas here). The goal is to release yourself and another from the negativity you may hold concerning a situation or a wrong seemingly or actually done to you. Everyone makes mistakes and forgiveness is a beautiful gift. But you should not forget the lesson of the situation or it may repeat. Forgive the grievance and forget the negative energy of it but always remember the lesson learned. Simple, right? ~Blessings of higher love and understanding.
(c) Jaie Hart 2012 (photo, random internet find)