I am a gift shop clerk for a museum. And a lady just came in and asked if our rock keychains were agate. I said "I am sorry, I don't know what that is so I am not sure". So she showed me a picture of it and I said "I am sorry, I'm not sure, but they sure look like it" (with a smile) and she rolled her eyes at me and said "you're an idiot, no wonder you work at such a low paying job worthless job". It really hurt my feelings because I did nothing to her and was so nice to her. I wanted to say well, I am a gift shop clerk, not a fucking geologist!