Well that's just terrible. I went to a trade school for learning audio engineering. One of the instructors always used a day to show "Spinal Tap" to his class. I didn't realize it was fiction for about the first 40m. The guy made some great films.
Amusingly, neither did Liam Gallagher until he was 30:
> https://www.loudersound.com/features/oasis-liam-gallagher-sp...
> "It's fair enough," he responded. "I was under the impression for some time that Oasis was a real band."
I'm dying!