60-day mapFive-Minute AI LessonsPart 1 · What AI Is

Why does AI forget what you just said? — Memory limits

If it matters, say it again.

1 · Think first

AI doesn't store a chat the way your brain does. Every time, it rereads the whole conversation so far from the top, then answers.

But how much it can read at once (its context length) has a limit, so when a chat gets long, the early part gets pushed out.

So for anything really important, bringing it up again later in the chat helps the AI and you.

2 · Experiment · Context window tracker

See for yourself how old messages get pushed out as a chat goes on.

There are only 4 slots. As the chat goes on, the oldest message gets pushed out first. Mention a pushed-out one again and it comes back in.

Inside the window (context) right now

Pushed out of the window (click one to mention it again)

Figure

The window has a fixed size. When a new message comes in, the oldest one gets pushed out.

Only messages 4–6 are inside the window. Messages 1–3 have been pushed out and don't count for this answer.

3 · Quiz

Three questions. Pick an answer and it's marked right away, with the reason why.

If it matters,
say it again.

How much an AI can read at once is called its context length, and lots of research is trying to make it longer — Lost in the Middle: How Language Models Use Long Contexts