What amazes me is that we pretty much are converting, just very slowly, one thing at a time. In school we all learn the metric system, and it's used all over in industry and government. At the supermarket, everything is labeled in both systems, and some things have started trending towards metric as the default. We are all used to the 2L bottle size. The old fifth of a gallon bottle, though some still call it that, has been replaced by the 750ml bottle. More recently the 20oz bottle has been phased into the .5L, mainly--I'm sure--to shrink the amount while keeping prices the same, but still it's progress in this regard.

I think the transformation will be effectively complete when highway signs use kilometers. But I don't see that happening any time soon.