It was a persistent and substantial bug, people jokingly suggested getting it a birthday cake because it was so neglected.
Care to tell us which one it is?
Probably the infamous "thumbnails in file picker" bug that is a meme on 4chan's /g/:
But that's not a bug. It's a feature request
So the only conclusion you can really draw from "one bug was 11 years old" is that they had been using that issue tracker for at least 11 years.