Touring a school's history department prior to interviews the Head of History showed us a shelf full of artefacts, held up a twisted metal spike and asked "Does anybody know what this is?" "A silent picquet?" I replied, when nobody else did. Correct. I saw something else on the shelf and politely asked him "Is that medieval pottery?", to which he brusquely replied "It isn't a quiz." Maybe he didn't know much about medieval pottery, but I didn't get the job - the internal candidate did. It didn't matter in the end as I got a better job later on.