Years ago (at this point, probably 29), I remember looking over an acquaintance's shoulder as he telnet'd from our school's 486s into a local community network, and from there checked his email. This was before GMail, before even Hotmail. Just pine running in some early Windows terminal client. And I caught a glimpse of an email and a snippet of text and ever since then, have periodically typed it into Google to see what I can find.
And it yields nothing, always nothing. References to something in a work by a reasonably well-known SFF author, but I know it's not that, because the phrase didn't appear in that context, it was in reference to something local. And so I shouldn't be shocked - this wasn't pre-web, but it was before the web had become part of the general consciousness. Organizations, and people, hadn't decided en masse, to make websites (remember when that was the thing?). Most things were still not online.
(As an aside - I wonder how much is still not online, existing in people's own memory, or fragile media, whether that's decades-old newspapers, stacks of floppies, or pamphlets and out-of-print books that will never be digitized. The internet's collective consciousness is enormous, but hyperfocused on the present and recent past.)
It feels strange, still remembering this, given all the things I've forgotten, to be still periodically poking at it, looking for something. A hit, a reminder, I guess, of what was kept hidden; what still is. I'll check again in a few years.