If you're of a certain age, you may have been told that whatever you put on the internet stays on the internet. While something can be kept alive on the internet for long periods of time depending on how many copies have been backed up somewhere, that's not really the case. In fact, a significant chunk of the internet's history has been lost to time due to link rot. Sites get shut down for one reason or another. Anything that's on the server that was hosting the site can and often do go up in smoke.
Websites like the Internet Archive exist where users can back up a website if they want, but it may never be a complete backup. Especially for websites with a large amount of user-generated content. And Internet Archive's survival is not guaranteed either. But it's the best we've got right now.
With that in mind, here are some archives of older stuff of mine that no longer exist. Some stuff may be missing.