Ok I might be stating the bloody obvious, but I can't find reference to it anywhere.

Levequests are memories that are distilled into leve plates via some process that causes them to reverberate with an Aetheryte which in turn forces us to Echo and experience them. This is what happened in the intro movie, right? I never really understood before that that was what we did each time we accepted/initiated a levequest.

Has the process of getting these memories into the leve plates been explained anywhere in-game?

Or did I just fail in understanding what's going on?