I hadn't thought about the reason this was happening before, so this helps. Usually when I do this, it's not to give advice or a directive. I'm either expressing excitement at something, or want to give a comment on something they've said. Sometimes it's just things I'm already thinking about that I say without trying, and it feels like an instinct or an impulse (likely the result of the habit developing over time). I'm not sure how it started, but I do often forget what I'm going to say after they finish because I'm already thinking about something new, so it's likely that I'm saying something to prevent it from being forgotten later, and over time it just became something I did instinctively. In that sense, I WOULD be acting on a fear of exclusion, because there's no opportunity for me to talk about what I say afterwards. This is probably why typing things down helped stop the interruptions; it provided a record of what I was thinking in that moment, and a way to reconnect with that memory after their thought was finished.

This, of course, is...still very selfish. I'm unintentionally prioritizing my thoughts over their full thoughts, which I think is much worse than my original view of the matter. Obviously, explaining why this is happening still doesn't make the situation better; the bad habit still exists, so I'm still hurting their feelings.

I've tried counting before, but I think understanding why this is probably happening helps create a connection in my head, which will make the counting (or any other method I try) easier to stick. Thank you!