I love just the ideas in the Erlang system. I've tried to break into it a few times, including once or twice with Gleam, and kept getting blocked by terminology I didn't know and couldn't look up, or instructions that didn't have the intended effect. I became convinced I needed a guide who already knows the system.

That was a few years ago, and looking back I must have been wrong -- but I tried pretty hard. (I successfully learned my way around Haskell and NixOS, which are at least roughly as esoteric, but I thought much better documented. And NicOS isn't even that well documented )