You are right, context helping is known. The investigation started with what the agent reached for when asked to get better. It could have reached for code execution, subagents, web search, or memory. It reached only for memory and spent the run building a knowledge base, so the natural reading was that the notes were the mechanism. The ablations say otherwise. Fresh sessions were booted from each element of the context and validated on the same 120 held-out tasks: the notes moved nothing in nine comparisons, the thought content decayed to nothing across the run, and the record of graded tasks with post-compaction summaries carried the improvement. As an artifact, the memories Claude Code wrote for itself had no effect on the improvement it was making. I think that is interesting.