My Grymoires are collections of esoteric spells I need to use only on rare occasions. The more mundane things are in the forebrain because of simple Spaced Repetition, but more esoteric things must be preserved.
I have a Shell Grymoire containing some really goofy shell pipelines and I should add more things in to it.
I have a Nix Grymoire that tries to describe the necessary a-priori information necessary to wield nixpkgs in anger.
I have an Emacs Grymoire with some of my most Messed Up Emacs hacks and init.el snippets and common functions and elisp patterns.
I have an Arcology Grymoire with random snippets of code that interact with my knowledge management system's data and metadata.
I probably would want a Python Grymoire!
I'm not a technopagan, gut I do keep my spells handy.