Yes only eternal God can forgive our sin and cast the guilt as far as East is from West
Forgiving to us is remembering we have forgiven others by obeying the commandment . Like all things God brings to our memory the things he has taught to include the work of forgiving as he works with us to make it possible.
Unlike the disciples that were in training. 7x 70 =490 times. If a person can keep track of that then I would think its time to evaluate ones own self. Sometimes when angry at God for bringing some new challenges into our lives we can look for fault in people. The easy way out..