In 2002, I was invited to speak at an IBM conference in San Francisco. When it came time to give my presentation, no one showed up.
I had forgotten about it until I was perusing the Wayback Machine and found the PDF of my old presentation.
The interesting thing is that the discussion in this doc is still relevant, even though the web is a very different beast than it was in 2002. Caching headers and their deployment have not changed much since they were introduced.
And there are still entities out there who get them wrong.
If you like ancient web docs, check out what webperformance.org looked like in 2007. [Courtesy of the Wayback Machine]