There's a similar thread on TSR which I found quite entertaining, so I thought I might as well start one here and see if it gets off the ground! I can start with a contribution to the 'stupidest thing you've said' side. Had an interview in January where the partner and I started discussing batteries. He asked me if I knew what they were made from. My mind went completely blank, so he took pity on me and said lithium was a core component, and did I know where it came from. Me [almost verbatim]: "Well... it's a chemical sort of thing, isn't it... in fact I think it's actually a metal... which means it doesn't grow on trees, and we don't get it from animals like milk, so... I guess we mine it from underground?"