Reading into the book of Revelation, there seems to be some mystery behind it.
Particularly:
When the seven thunders spoke, I was about to write. But I heard a voice from heaven saying, "Keep secret what the seven thunders said, and do not write it down." - Revelation 10:4 (NLT)
Why wasn't John (assuming he actually wrote the book of Revelation) allowed to write down what he heard? Was it to prevent false interpretation and/or claims of the end times? What was the purpose of keeping what the "seven thunders" said a secret according to a Catholic perspective?