Funnily enough, one of my favourite stories is from the period I worked in an archive. I was supervising the area where people viewed the original documents and this guy came in and wanted to use a fountain pen to take notes. This was very much not allowed, pencils only!

When I was firm about enforcing the rules, this guy accused me of wanting to steal his (very boring) pen. I didn't care less about fountain pens at the time. The whole thing was ridiculous - I was 17, he was 50ish. But I was perfectly polite to his face. Less so in the staff room later!