And, when they find out that their recipient is a(n in-universe) fictional character:

> Captain Groenback was a spook for rich kids. It was ridiculous: a magical golden ghost ship looting vessels of their earthly possessions, circling the archipelago forever without hope of a port, looting unwisely crews, who were then cursed by the same fate.

(Of course, in-universe, Captain Groenback was a real person - she was erased from history by becoming a legend. Legends are tricky things - you always learn if the people in the story were real after the fact.)

Here's the thing - we've been telling ourselves stories since before we wrote stuff down. In the absence of anything better to do, when prehistoric humans sat around the fire, we described to each other images *beyond* our earthly reality - things too good to be true. Because it was fun.

The late, great Sir Terry Pratchett reminds us of what the first stories probably were about:

> Guys sitting around the campfire telling each other stories about the gods who made lightning, and stuff like that. They did not tell one another literary stories. They did not complain about difficulties of male menopause while being a junior lecturer on some midwestern college campus.

https://www.goodreads.com/quotes/9654148-o-you-re-quite-a-writer-you-ve-a-gift-for-language

I might be talking completely out of my ass, and an anthropologist might know better, but wouldn't the whole point of telling stories about those gods be the extraordinary premise?

Either way, Tolkien's proviso - Thou Shalt Not Desecrate My World of Fantasy - is the very edifice that Pratchett's Discworld shattered into a million pieces. Daniel Luthi explores this is in an essay on Discworld as a 'postmodern playground':

https://dc.swosu.edu/cgi/viewcontent.cgi?article=1036&context=mythlore

Discworld is self-aware. It knows that you know it's ridiculous. It agrees. Pratchett was never afraid to take the piss out of the world that he created. His footnotes are often a way for the narrator to take you aside and make fun of the new piece of Lore that's just been introduced:

> The idea that Winter could actually be enjoyable would never have occurred to Ramtop people, who had eighteen different words for snow.*
*(All of them, unfortunately, unprintable.)

- Wyrd Sisters, p88

Talking of Wyrd Sisters, there's one scene in my mind that sticks out as pure Mum.

Our three protagonists - Esme 'Granny' Weatherwax, Gytha 'Nanny' Ogg, and Magrat '' Garlick, all witches - go to see a play. It's touted as a professional production, but Pratchett frames everything as though it were a Punch and Judy show - just sacking curtains and planks of wood laid over barrels.

And yet:

> [The theatre] had also managed to become The Castle, Another Part of the Castle, The Same Part A Little Later, The Battlefield, and now it was A Road Outside the City.

Granny Weatherwax watches a king being murdered in the play, and calls bullshit:

> "He's killed him," she hissed, "Why isn't anyone doing anything about it? […] right up there in front of everyone!"

Magrat grounds her fellow witch to limited success. The next scene in the play is a long soliloquy by the murderer, and how he's filled with so much regret:

> Granny was not to be distracted. "What'd he go and kill him for, then?"

Nanny Ogg jumps in as the mediator:

> "I reckon," she said slowly, "I reckon it's all just pretendin'. Look, he's still breathing."
[…]
The corpse tried to shuffle its feet behind a cardboard bush.

But Granny's one of Discworld's sharpest minds. She doesn't need Nanny's comments to know the charlatans on stage are 'purveyors of untruth and artifice.' In a later scene, the actor playing the dead king fills the role of a soldier. Granny calls bullshit once more, and looks for the actor who previously played the murderer (presumably he's in a different garb - maybe he isn't):

> "He done it!" she shouted triumphantly, "We all *seed* 'im! He done it with a dagger!"