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!"

Things don't just stop there, though - no, no, no. It's a well-known fact on #Discworld that Witches can go wherever they like. The three of them head backstage…

> "You!" [Granny Weatherwax] shouted. "You're dead!"

That, he was. And there, after a fake bush meets a Lancre steel-capped boot and bursts into splinters, she exposes the lie to the world at large:

> "See?" […] "Nothing's real! It's all just paint, and sticks and paper at the back."

But when you think about it, Granny Weatherwax, in her own abrasive way, critically (and literally) deconstructs the secondary world that the production asks the audience to believe.

How did Mum prove to Dad that dragons aren't real? She googled for dragons and found their Wikipedia page:

https://en.wikipedia.org/wiki/Dragon

For the same effect, she could've looked up some behind-the-scenes videos of the actors flailing in front of a greenscreen. None of it's real.

So, what's all this simulacra and simulation business, then? When we see a White Walker or a dragon on-screen, what relation do they have to our reality? That is: what does Mum mean when she says a dragon isn't 'real?'

I'll start with something that reflects the real world, one-to-one: a photograph. If you're looking for a place to eat while abroad, you're most likely going to look at the unedited photos of food by previous patrons to know what you're getting into. If you can trust that the photo hasn't been edited at all, then it's as true a reflection of reality as we might get.

A step up from that, we might take photos from the business with a grain of salt, because, if they're not edited, they're at least trying to show the business in a manner that doesn't reflect real life. Mum and Dad experienced this first-hand last year: they booked a hotel based on very clean-looking photos, only to find their real room in squalor.

Another example might be cleaning your home for an estate agent to take photos. The state of the house in these photos does not reflect the tidiness of our day-to-day lives, because they are intended for potential buyers for whom this might be their 'forever home.' They don't want to see or imagine the dirt that life tracks around the house. That comes later.