Have I really forgiven someone if a situation causes me to remember it and feel the pain all over again?
Yes. Forgiveness does not mean the same thing as being forgetful. It would be foolish to be hurt by an abusive relationship to which you return again and again. You will obviously retain the some memory of the injury and probably feel the same hurt whenever it is brought to mind. The point is choosing not to bring it to mind over and over again and cause the wound to grow and fester.
Forgiveness is about choosing not to seek retribution or alienating the person for some hurt they may have caused. Forgiveness covers the wound but does not wipe its memory out of our minds. It is an activity whereby we try and seek resolution and healing but don't jump back into an abusive situation. Forgiveness is about moving on with your life and leaving the bitterness and anger behind.