At the time I had somewhat recently come out as trans to all my friends and close family. I had at that point completely shifted my online identity from the old username I had used everywhere for 20+ years. I was sitting at my computer, though I can't remember what I was doing at the time, when I got a message on Steam simply asking "Hey who is this?"
I vaguely recognized their username, but at the time my friend list had a lot of people I have never actually talked to so I had to think for a while before remembering who it was. Turned out to be an old roommate I lived with for a year like 6 or 7 years prior, and we had just never kept contact after they moved away. It was at this point that I remembered that my current Steam name was "Hex: Gender Dysphoria"(a reference to Dead By Daylight, a game I was playing a lot at the time.)
So I explained that I was [deadname] and we were roommates several years ago, but that I since came out as a trans woman and now go by Bridget. She congratulated me on coming out, then explained that she had also come out as trans in the intervening years, and she messaged me because she noticed she suddenly had a very obviously trans person in her friend list and had no idea from where.
We talked for a while and each expressed happiness at the other's journey leading to a better place. We haven't talked much since, but this interaction was a big deal to me in my fledgling transgender phase, and I like to think it was to her as well.
Moral of the story: Silly joke Steam names are good, actually.