Why chatbots make things up — and why more data doesn't fix it

Here's a puzzle. Ask a chatbot about a book that doesn't exist, and it might give you the plot, the author, and the year it was published. All made up, all delivered with total confidence. Why does it do that? It isn't broken, and it isn't lying. The real reason is genuinely beautiful, and once you see it, you will never be surprised by it again. This is Foundations, lesson one.