I was in a big class on production equipment a few years back for work. One of our vendors put it on as a training type deal. There were a bunch of engineers for major companies like Conoco there. I and one other guy were the only two non-engineers.
It was brutal. We couldn't get through 5 min with out tons of questions that had nothing to do with nothing. Even the people putting it on were getting wore out.
The guy leading the deal, was who I dealt with and ordered through. At one point he said, you know when you are look at a... then he said some piece of equipment I can't remember. The engineer guy responded... well I've never actually seen one of these in real life.
I literally said... F me... out loud and walked out. I went and hung out with some other guys I knew until lunch. The guy leading the deal came out and in to the office where I was and was laughing. Then we were trying to eat lunch and they wanted to talk about it more.
We still joke about that now. He ended up having to take the whole class out to the shop to look at the equipment because quite a few had never seen it in real life.
... and these guys were involved in designing prod facilities having never seen the equipment in real life.