So I have the same issue when I'm at work and also at home, not being able to write things down due to being busy in the middle many things at once (dad and husband stuff typically).
The quick answer is I repeat it back to the person/s. Also knowing what is being talked about is important.
When I'm at work, I make sure I fully understand what we are discussing. When you understand the topic, it much easier to remember it. If I have to ask questions I will. I also practice stopping all discussion and repeating back my understandings, which gives me a solid view on discussion and I find it helps me remember due to running it through my mind and verbalizing it.
When I'm at home and I'm being asked things or told things when i'm in the middle of something, I will verbally repeat it to my wife. I also know that part of my "bad memory" is because I auto pilot. I've gotten better at telling my wife "sorry, I just realized I wasn't actually listening when I said yes to all of that", then I have her repeat it back to me. Then I repeat it back to her.
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