I have a very occasional player who gives me a disproportional amount of difficulty as a Dungeon World GM. DW is normally really easy to teach to new players because it has almost everything a player needs on their character sheet—but it pulls off that trick by heavily leaning on knowledge of pop-culture and fantasy tropes that it assumes players have.
This player, though, turns out to be blissfully unaware of the vast majority of pop culture references and genre tropes that appear in the game. They picked the Paladin, and it took me two game sessions to realise that they had no idea what a "oath" meant, what a holy symbol is, and what a paladin actually was. As I've gotten to know them, I've learned that this isn't just a lack of fantasy trope knowledge, they're just generally unaware of and disconnected from the world outside of their life's focus (they're a dedicated visual artist).
They're not a regular player (art keeps them very busy), but when they do play I want to do right by them. I just have no idea how to help them play this game, which relies so much on assumed knowledge to provide the flavour that is at the core of its improvisational engine.
How do I GM better for this one player, who knows none of the fundamental tropes of Dungeon World, in a group that otherwise has this stuff down pat?