I learned a little more about why people have such a hard time with bitcoin's "intangibility" while talking to my mom last night. I asked her what it was like when credit cards were invented, and she explained that before electric cards there was something called a "charga-plate": https://historyofinformation.com/images/Screen_Shot_2020-08-18_at_5.41.58_PM.png This was a metal rectangle you would present at shops, which would be pressed into paper to create an authenticated artifact of the transaction. The precursor to charga-plates was just regular paper checks. In either case though, the mental model is the same, and credit cards simply extended the same mental model of having some physical cash in the bank (whether or not that is strictly true), and authorizing someone else to talk to your bank and pull some out. Bitcoin completely breaks this mental model. The problem isn't that it's intangible, because we've been using intangible money since the 16th century. The thing that breaks people's minds is that it is intangible, and has no custodian. When you sign a transaction, who are you authorizing, and to request money from whom? It really doesn't make any sense from the legacy money perspective to authenticate ownership of a UTXO with cryptography, broadcast it to an etherial network, *pay* one of several miners to include your transaction in a "block" (?) so that the math money can be split and some handed to your counterparty. Anyway, I think this difficulty might exist for nostr as well. Credentials authenticate you with the account holder, but keys authenticate your content with the reader. To make this worse, users have to custody their keys, making them the account holder and custodian — and when they log in to an application, they have to ask themselves permission to create self-authenticating messages! Weird.