It is not "forgive and forget" as if nothing wrong had ever happened, but "forgive and go forward," building on the mistakes of the past and the energy generated by reconciliation to create a new future.
The friend who can be silent with us in a moment of despair or confusion, who can stay with us in an hour of grief or bereavement, who can tolerate not knowing, not curing, not healing, and face us with the reality of our powerlessness, that is a friend who cares.