Oh gosh... Client (its not a very familiar term to people outside of desk jobs), notes vs posts/tweets, protocol, broadcasting (I'm still kind of lost on how that works) NIPs had me totally upside down. Relays vs servers (and how they tailor ux). Lightning I was familiar with but zaps was new. There's been a lot of clarification on that subject since the concept itself is totally new. And frankly, that's super easy to grasp once the pieces are in places. I realize it's like essay writing, show your work then hide it on your final draft, but if widespread adoption is going to come before that point, people are going to need help.