XML pioneer and early blogger Tim Bray went looking through Google for
some posts he knew about from 2006 and 2008 and found that Google
couldn’t retrieve either of them, not even if he searched for lengthy
strings that were exact matches for text from the articles; he concluded
that “from a business point of view, it’s hard to make a case for
Google indexing everything, no matter how old and how obscure,” and
so we could not longer rely on “Google’s global infrastructure as
my own personal search index for my own personal publications.”
The good news is that Bing and Duckduckgo both maintain much more
complete indices of old posts and publications, and so if you’re looking
for stuff that’s more than a decade old, you can switch to one of
Google’s competitors to find it.