Have you uploaded a video to YouTube, not watched it in quite some time, then re-visit the video after a couple of years, only to find the video has somehow gotten "corrupted" over time? That has happened to TWO videos I uploaded a little over two years ago. One, which I'll have to re-encode from the VHS again before I can re-upload, won't play at ALL, just says the "video is corrupted". The other, which was a 7:56 length video of an online friends visit here in 2007, played rather "jerky", and ended 1:28 into it, luckily I had a DVD backup of that one, and re-uploaded it earlier today.
Didn't discover the corruption until two days ago. I was telling a friend how my cat likes to carry a toy "Kermit the Frog" around the house, while meowing at the top of his lungs. She thought that might look funny, and I knew the cat was caught on video doing that back when my other friend visited in 2007, so I gave her a link to the video, which, she alerted me, had no cat anywhere in it. I went to look, noticed the video was totally farked up! Next time she is online, I'll have to direct her to the video again. Just checked before making this post, it is currently still playing properly.