Why do AI agents forget things between sessions?
Because most of them, by default, have no memory to begin with. Whatever an agent "knows" mid-conversation lives entirely inside the context window, and the context window empties the moment the session ends. A demo that feels sharp on day one can ask the exact same onboarding questions on day two, not because the model got worse, but because nothing about the previous session was ever built to survive it. What looks like memory in a good demo is usually just a long, expensive prompt.
This isn't a flaw specific to one tool. It's a structural gap in how most agents have been built so far and it's the thing that separates an impressive demo from a system a team can actually depend on.
Won't a bigger context window fix this?
Not really, and for three fairly practical reasons.
