“Alligators can grow up to 15 meters...”, You’re right. The joe doesn’t work with the metric system. That being said, in the USA I have to admit that 2-Liter bottles and 9mm bullets have caught on pretty well.
precisely ;) Yeah, but those are the only two... apart from scientists nobody uses it and even they get it wrong sometimes... And it really doesn't help that the conversion is so weird.