Yes, it’s from a book called “Uncle John’s Bathroom Reader” and that book was resting on a closed toilet seat in a nation that only kind of uses the metric system in certain situations… however, you’d be surprised how much you can learn after a single visit to any local fast-food joint!
Because I have had to work with American companies as part of my job for the past couple years. For the entirety of my personal life and the rest of my professional life I use metric. I’ll grant you I should have said ‘almost exclusively’ in my previous comment, but I think that’s just splitting hairs.