My wife has a near perfect memory and can remember every story I've ever told her. I don't have the best memory either, so I always get nervous and anxious that I'm going to say something wrong when she starts pushing a question onto me. This usually results in an argument where she says I'm lying or trying to hide something (which I swear I'm not).

I was in a relationship where my partner convinced me he had an amazing memory for conversations and constantly threw things in my face, similar to your wife's behavior. My partner did not have a better memory but he was much better at convincing me that i was wrong. It got to where i questioned everything i said and felt tremendous guilt thinking I'd be caught in lies. I would over explain everything and i still catch myself worried people will think I'm lying.

The first thing you need to do is stop believing she has a better memory or that that even matters. She doesn't and besides that memories fade and change with time. Do not engage in old arguments, do not rehash what has already happened and has been squashed. Second, start documenting conversations with her. I found writing down my conversations improved my recall tremendously. I don't document every conversation but for a while i did and it improved my recall but especially my confidence in what was said. This will also help you see any patterns in you or your wife's behavior in these arguments. If you can, couples counseling or even individual therapy can help you work out better strategies for dealing with memory and recall and how to engage/disengage from a baited argument.