I'm working out why I found that so utterly flattering. I mean, Person X isn't someone that I know well, and I certainly don't know if Person X is a good writer, so it's not the comparison thing.
I guess maybe it's just that I'm pleasantly surprised that it shows that I'm always writing. That it's something that's noticed and generally accepted to be so.
Let this be a bookmark. I shall come back and puzzle upon it more later.