We went through the same process in Canada at about the same time. It was tough for me- I was 10 or 12 at the time, and had learned imperial measures (feet, pounds, farenheit). I still tend to do more conversions in my head than I should. It’s too bad that the U.S. didn’t stick to the metric system- part of the reason why I still do conversions is because I deal with folks in the U.S. fairly regularly- saying “it’s 20 degrees today” can cause a lot of confusion!