When I did my geography exam at 16 I'd given up with normal revision, so I spent the morning reading about one particular extremely obscure topic - something li

When I did my geography exam at 16 I'd given up with normal revision, so I spent the morning reading about one particular extremely obscure topic - something like the natural resources of Nigeria - because it was on the back of the weekly installment encyclopedia my parents were buying for me. It hadn't been mentioned in class. It hadn't even been mentioned as a possibility. But it came up anyway. I wrote a nice little mini-essay on it, and I aced the exam. I suspect that happens a lot in exams and job interviews. You get $random_question and it's supposed to be a test of broad knowledge, because clearly if you know the domain you'll know $random_answer. But it doesn't exclude people who are lucky. (Or possibly mildly precognitive.)