It is not enough to reply to an apology with "it's fine." Like so much in relationship dynamics, forgiveness involves both an internal process and an expression of that internal process. In this case, the internal process is letting go of the imbalance. The expression is letting the other person know that this has happened.

It isn’t uncommon for forgiveness to be made into something much more complicated, messy, or even impossible to do than it actually is. Sometimes these ideas are things we believe that get in our way of forgiving. At other times, they are things that other people tell us that forgiveness is or contains. And then, some things fool us into thinking we've forgiven when we haven't.

When people talk about wanting you to forgive them, they're frequently talking about three very different things (often without even knowing it): rebuilding trust, healing from emotional pain, and (actual) forgiveness. Mixing these three different items is a recipe for frustration and disappointment.