Somehow, I seem to have ignored this stubbornly and instead bookmarked pages, downloaded videos and copied strings (!) out of the web for years.
Not that it did me much good, I now have thousands of inconsistently sorted bookmarks and a bunch of directories filled with assorted data.
What this article tells me (again), is that because you can't trust search engines to behave in a predictable manner, you can't even be sure you'll be able to find the stuff that you know is online.