When we're old, our lives become the sum of all whom we have loved. It is important not to waste anyone. One task of living out the last half of life is excavating and recovering all of those whom we loved the first half. Thus, the recovery of lost loves becomes an important way in which the past affects the present.
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.