Picture what a single AI session leaves behind. As of 2026 the common version of this looks like typing into a chat model such as Claude Fable: you open it, describe what you wanted, correct it twice, and get something good. The interface keeps changing, to voice, to glasses that carry world knowledge, to earbuds, someday to a brain-computer interface and to systems more capable than any person, but the shape of the loss is the same in all of them. The output is in front of you, and the reason it turned out well is not. The specific instruction that fixed the second draft lives only in the conversation and in your head. Close the session and that reason is gone. Next week you start the same kind of task from a blank page and rebuild the same correction by hand.