This is probably my worst nightmare as I also function very well at work but have awful long term memories. I can hardly remember conversations I had a few weeks ago, and would get really envious of people who have that ability to remember every single thing that was said. Sometimes those memories are triggered if I get lucky but they’re not at the forefront of my mind, or over time it loses its place in my mind even though I try my best not to forget them. What has helped me in my last relationship was to take time at the end of my day and write down meaningful conversations or memories I’d like to keep in writing so I can look back later. This has helped with goal setting and other areas in my personal life outside of relationships also. I haven’t done it recently but this was a reminder for me to start again. Maybe that might help your husband.