A context window is a per-run input, not memory; conflating the two means the agent discards all learned experience at session end and must rediscover it. This frames memory as an architectural layer separate from the inference context, not something the model provides.
Forces a design decision about where persistence lives: if memory is not a layer, multi-session agents will repeatedly reproduce failures, burn tokens, and hallucinate because they re-derive the same facts from scratch.
Any long-running or multi-session agent needs an external, durable state layer whose lifecycle is independent of the model's input window.
Context windows are input for the current run and are tossed away at session end, leading to repeated work across sessions.
Session B starts fresh and has to re-read files and guess again.