> what did i get wrong here?

You don't know how an LLM works and you are operating on flawed anthropomorphic metaphors.

Ask a frontier LLM what a context window is, it will tell you.

It's a fair question, even if it might be coming from a place of misunderstanding.

For example, DeepSeek 3.2, which employs sparse attention [1], is not only faster with long context than normal 3.1, but also seems to be better (perhaps thanks to reducing the noise?).

[1] It uses still quadratic router, but it's small, so it scales well in practice. https://api-docs.deepseek.com/news/news250929

Parent is likely thinking of sparse attention which allows a significantly longer context to fit in memory