"I worked at a restaurant for a while, and I once had a customer who as soon as she sat down said, 'I'm vegan, I'm going to need a special menu.'
I responded, 'We don't have any special vegan menus, but we can customize a dish for any dietary needs or preferences.'
As if she had already made up her mind, she said, 'That won't be necessary. I'll just have the Parmesan Tilapia.'
I informed her that the Parmesan Tilapia wasn't a vegan dish.
She asked why, and I said, 'Tilapia is a fish. Parmesan is cheese, and therefore an animal product.'
She looked me dead in the face, scoffed, and turned to the people at her table and said, 'Our server doesn't know anything.'
Then she looked back at me and said, 'Tilapia is a fruit. I've been to a Tilapia orchard. Parmesan, since you don't know, is made from grinding eggplant root. How did you even get a job in a restaurant??'
I stared at her for a solid ten seconds and tried to figure out if she had been messing with me. She demanded to speak to the manager. That made it clear that she hadn't been joking. Meanwhile, everyone looked down and avoided eye contact. I got the sense that they all knew it was best not to challenge her and to let her have her way.
So I served her the Parmesan Tilapia and she ate it. She had no questions and no complaints. She didn't send it back.
When she finished her meal, she decided to talk to the manager again on the way out, after not tipping me. She complained about the service, about how we didn't trust her and said she hoped we felt terrible about it. But also said the food was good.
On her way out, I told her to look up the word 'Tilapia' on Google and see what came up. We never heard back from her."