One of the students just asked about Roman numerals. So I took a minute to explain them and how they count up, one through eleven. She was particulary perplexed by how IV was four and not six.
"That's not how I was taught, and I'm part Greek."
"You never have more than three 'ones' in a row. If the one comes before a bigger letter, you subtract, not add."
"That's not how my grandma did it. This was passed on in our family. History must have been changed."
How do I argue with that? This apparently is a conspiracy on the level of the da Vinci code.