if you add a notebook—if you write down short summaries of what you talk about so you can return to it in later conversations and expand

Because I had the notes, I would review them if I was to speak with the same person again, adding comments about thoughts I’d had in the interim, rank ordering which topics I wanted to revisit, and so on.

While talking, we would take turns jotting down keywords to aid our memory, and then, when I got home, I would add what we had said to my note-taking system. I revised old notes in light of how our thinking had evolved, adding new links between different ideas, and so on.

If Torbjörn wanted some of the notes, I would email edited excerpts to him, so I didn’t have to format my notebook in a way that makes sense for him to read.

, I would occasionally revisit the notes and add a thought or two. It kept the conversation alive in my mind. I’d update a list of topics I wanted to cover next time, shuffling their relative importance.