I said I forgave my partner, but I keep using the mistake in other arguments

We were arguing about an unwashed saucepan when I said, 'Well, remembering things isn't exactly your strength.' We both knew I meant the night my partner forgot to collect me from the station.

That happened four months ago. I got home another way, we talked about it, and they apologized. I said I forgave them. Since then, whenever I'm losing a small disagreement, I can bring that evening into the room with one sentence.

Some hurt remains, but I've stopped using it to explain what I need. I've been using it to make my partner the person whose argument counts less.

How do I stop without pretending the original night no longer bothers me? I'm worried that admitting this will sound like a request for a bigger apology, when the thing I most need to own is what I've done with the first one.