I had the _exact_ same feeling; when I read your comment I started googling a bit but I came up short. In my case it should probably have been one or some of: MUDs, Linux, Debian, Amiga, shareware, usenet, IRC.
http://hep.itp.tuwien.ac.at/~www/particle/Doc/debnotes.html
Debian 1.x/2.x days, likely a prominent mirror?