Do we have an obligation to forget sins done us?

A reader writes:

My question regards forgiveness.

Modern psychology asserts that it is healthy to forgive
but not necessary to forget. Even from the pulpit I hear this.

Reflecting and praying on this I cannot agree.
I think that forgiveness is a process sometimes very difficult,
a rational choice. When with the grace of God,  I forgive and also
pray for the grace to forget. Whenever I remember, I pray for the
person I have forgiven.  I believe that forgetting completes the Christian
process of forgiveness. If we are to enter by the narrow gate,
I think that we have to let go of the baggage in which we carry the hurts.
What are your thoughts?

I disagree.  You can ask for the grace to forget, but the reality is that we often can’t.  And placing a moral obligation to “forget” on the shoulders of somebody with, say, Post Traumatic Stress Disorder from, say, a rape is a cruel and unnecessary burden.  We can choose to forgive.  We cannot choose to forget, we can only ask for the grace to do so and then move on.