I remember the metric push, but the problem was we never got rid of the old measurements. I think if we'd had road signs in kilometers without miles, people would have figured it out pretty fast. As it was, it was like trying to learn a foreign language by using a dictionary and converting everything, rather than natural conversation. Nobody bothered learning metric because the old, familiar measurements were still around.
It's not just older people. I have seen kids' rulers in the stores that don't even have centimeters on them, just inches. Except at the doctor's, and then only sometimes, weight is in pounds. Temperature is always in fahrenheit. Most people would be baffled to say what a comfortable cesius temperature would be. 30? You're kidding.
It made traveling in Canada challenging, at first. It was very easy, however, to pick up metric when there was no alternative. That's what the US should have done.