And if they do, they will call it things like "square doorknob".

Except for those few of us who grew up interested in science, because science pretty much world-wide (even in the USA) uses metric for pretty near everything. I've used metric for my entire life, and been ridiculed for it that entire time by all the same morons that think any interest in science makes you a "nerd" even if you also happen to play and enjoy sports (despite almost the entire rest of the world standardizing on metric long ago), and despite the fact that most folks in the USA are already using metric themselves every single day. Yet somehow metric is "too hard to learn, waaah!" (It's based on tens, just like our money. Too complicated? Gimme a break!) Hell, our sugary fizzy drinks even all come in 1 and 2 liter bottles, FFS!