The half-buried memory that surfaces when Carl tries to place where he first heard of the Inevitable Ruin.
When Juice Box asks whether he has heard of The Inevitable Ruin, Carl recognizes the phrase without knowing why. He has never read it, it does not appear anywhere in the Dungeon Anarchist's Cookbook that he can remember, and yet the idea is burned into his bones.
A single unbidden thought answers him: do you remember the circus? He does not pursue it, and instead gives Juice Box the definition he somehow already knows.
Buried memory that seems to be the true source of Carl's knowledge of the Inevitable Ruin.