We count what you forgot
In their arithmetic, forgetting is a positive number. Every concept a later generation failed to inherit was given an index and filed in a quiet archive, seven layers deep. When a civilization forgot the color of its sun, it placed the memory in the seventh layer, sealed the door, and continued.
Their last transmission was not a warning. It was a receipt — a list of things they had recently placed in the archive, in case anyone downstream still remembered how to read.
— End of transmission. —