Growing up with SI units, the only times I am forced to use Imperial units of length is when I help my parents with their parking.

Today my father was reversing his car after my mother and I got off. “Half a foot,” I announced as I looked from the side, estimating the distance between the car and the wall. My mother quickly responded, “That’s clearly less, it’s more like three to four inches.”

After my father got out of his car, I invited him to take a look. “About eight inches to a foot,” he estimated.

I went inside and took out a tape measure. It was exactly six inches (plus or minus 1/4 inches).