You can hate Moxie or like him but I'll add a video here which is a good explanation how PGP, OTR, Diffie Hellman key exchange and Axolotl works. It's explained so that most people get bit better understanding of the encryption software they are using even if they don't have too much knownledge of the concept.
You can rewind to 12:50 and it lasts maybe 10min. I have shown this to clients many times even it's from year 2014.
I like this thread because people don't take this stuff seriously. It's not about that you have nothing to hide but it's the right to your
privacy. Think that maybe you send a message to you relative about stomach problems and then you get call from insurance company that they will raise your health insurance because you have stomach problems. It was a private conversation, but I guess you have nothing to hide and it shouldn't bother that they have listened in on your conversation. We all have things that are private, it's part of what makes us persons and creates your own identity.