One can be "semi-famous", as OP said, in small circles, Eg. chess, and you wouldn't recognize his username--but maybe lots of chess players would. I didn't see

One can be "semi-famous", as OP said, in small circles, Eg. chess, and you wouldn't recognize his username--but maybe lots of chess players would. I didn't see it as humblebrag anyway, since it was a true part of his points.