True story:
I was visiting my in-laws in Florence, Italy a couple years ago. My father-in-law had found a DVD of a comedy he loved as a kid, and he had just bought a DVD player so he could watch it. We managed to get the DVD player hooked up, and he started watching the movie. Sure enough, it proved to be very amusing and he was soon laughing hard. After watching the movie (bear in mind, I don't speak any Italian), he said it was great, but he didn't realize that back then everyone was speaking with Mickey-Mouse voices in order to make everything seem funnier. He had somehow forgotten that part of the movie, or else didn't realize it when he was a kid. The next day, he went out and bought a few more old favorites of his. He started watching, and then got a funny look on his face, when everyone in those movies was talking too fast, too! I still don't understand how it happened, but the audio settings on the DVD player were screwed up and everything was double-speed. I find it impossible to believe that it was just the audio, and not both the audio and video, but I don't recall anyone noticing anything out of the ordinary about the video itself. Maybe it was just because it was an old movie, and we all just assumed that the fast movements were due to the original being filmed at a lower frame rate, which often leads to old movies looking a bit off when viewed at modern frame rates? No idea...