Forgive and Forget?

I have had a lot of conversations through the years with friends, family members, and co-workers about forgiveness.  I also recently received the following email from Jim's Daily Awakenings:

Do you know what an Etch-a-Sketch is? Perhaps you had one when you were a child. It is a toy that enables you to draw things on a screen by moving two knobs: One produces a vertical line and the other makes a horizontal line. When you manipulate the handles effectively at the same time, you can create a lovely picture.
The thing I like about an Etch-a-Sketch is if you do not like the picture you make, all you have to do is shake it and then the picture goes away. Every time I see an Etch-a-Sketch I think about how wonderful forgiveness is.
The good news is that the One who made you has a great pardon without parole program. He gave us the chance to start over on the same terms that we had at the beginning.

This really made me think.  I love the idea behind this email and I understand that as a Christian this is the ideal that I should strive for but at my core I am human.  I may forgive but unlike an etch-a-sketch I can't just wipe the slate clean.  Sometimes the deed that needs forgiving is too deeply etched to simply go away.  Does that mean that I hold on to the hurt?  No, I strive for forgiveness, not so much to ease them but to ease myself.  I know that holding onto hate and anger causes me more damage than it does them and besides, I don't want that other person to have that much power over my life.  However, forgiveness can't always equal forgetting.  Simple hurts can be forgiven and forgotten but others just can't.  Does this make me a bad Christian? I certainly hope not but if it does I will just have to live with that.