It happened at a meetup for developers who were mostly in their twenties. Someone was showing an old file icon, the little square with the metal slider, and asked out loud “why does the save icon look like that?” The room laughed for a second and then got quiet, because a genuine answer was needed and I was the only one who knew.
I explained floppy disks. I saw one person open their notes app. It was funny, briefly, and then it kept being interesting for weeks. Because a small shift in status had happened in that room, and I had to notice it. I was no longer the person receiving advice; I was, at least sometimes, the person people were quoting later. That is a responsibility I was not ready for.
Two changes came out of it. First, I got better at explaining things. Not simpler — better. The stakes went up because the room was actually listening. Second, I got quieter in conversations where I did not know as much as I felt I should. Because the older person in the room has a different obligation: not to fill the silence, but to make room for the next person coming up. Both changes are still holding, three years later.