What is context, and why does my chat get worse?

Context is everything the AI can see right now: your messages, its replies, anything you pasted or uploaded, and the instructions behind the scenes. That is the whole of its world for this chat. It does not remember yesterday and it cannot peek at another tab.

Think of a desk. Every message puts another sheet of paper on it.

Why the desk fills up

The desk has a fixed size, and that size has a name: the context window. Early in a chat it is clear and the AI can see everything at once, so answers are sharp. An hour in, the desk is buried. Your first instructions are under forty sheets of back-and-forth, half of which were dead ends.

Two things happen then. It starts to miss things you said at the beginning, because they are buried. And it gets slower and vaguer, because it is reading the whole pile before every reply.

Pasting a huge document does the same thing in one go. One long PDF can fill most of the desk on its own, leaving no room to think.

What to do about it

Start new chats more often than feels natural. One job, one chat. When the job changes, the chat changes.

Carry over only what matters. Before you close a long chat, ask it to write the handover. The handover prompt is the one I use.

Put the permanent things somewhere permanent. Who you are, how you like answers written, what you are working on. That belongs in your settings or a project, not retyped into every chat. Tell it who you are covers that.

Try it on the chat you have open now

If a chat has gone stale, paste this before you give up on it.

This conversation has got long. In five bullet points, list the decisions we have made and
the facts I gave you that still matter. Leave out anything we abandoned. I am going to start
a fresh chat with just that list.

Paste them into a new chat and carry on.