Because I'm American, so I use metric in scientific contexts, and weird medieval units in everyday ones :-)
I'll edit a bit for clarity for you all who live in more consistent places.
I'm not above asking the barber to leave an inch on the top, but then I'm not going to ask him to leave 15mm on the sides. At least keep the system consistent within a sentence :)
I'm not above asking the barber to leave an inch on the top, but then I'm not going to ask him to leave 15mm on the sides. At least keep the system consistent within a sentence :)