On the other end, it's fun when you encounter a bug and go search for an answer and end up reading an answer on Stack Overflow that _you wrote_ 5 years ago and totally forgot about it.
Haha, this happened to me for the first time recently. Asked a question, didn’t get any answers, ended up updating my post with the answer I eventually found. Even had a couple of responses thanking me for the follow up. Five years later, ran into the same problem and forgot the answer, my answer was the top result on google.
I was once looking to see if there were any projects or discussions regarding <insert niche domain> via the google search "<niche domain> Hacker News". I clicked on the top link because, read the comment, and was annoyed that it didn't actually address the <niche> things I wanted it to.
Then I realized I wrote the comment. I didn't address the <niche> things because I was looking for it then and I'm stilling looking for it.
Equally fun is using a package or a part of it that you haven't used for a few years and going to read the docs for a certain feature... and realising you're the one that wrote those docs :)