Why Models Answer Confidently When They're Wrong: Hallucination Isn't 'Not Knowing,' It's a Side Effect of the Mechanism Itself

Use Claude for a while and most people run into an especially confusing situation: the model states something that sounds confident, specific, and doesn't waver in tone at all — and it turns out to be wrong. This hallucination phenomenon is often intuitively understood as "the model doesn't know the answer but forces one anyway," but that understanding is only half right. More precisely,...