I hear you on the difficulties caused by the USA living in an Imperial world! The Mars Climate Probe!!! Damn!

I come from a dedicatedly metric country (the land of Oz) and we went metric when I was in Grade 1, so my entire measuring life has been decidedly metric.

And yet, I am 5'3.5" tall! I weigh myself in kg. I buy fabric in metres and talk about things being 6 inches long, or two feet away! I buy diet coke by the litre and cook using cups of milk and tablespoons of butter! My baby was 8lb 12.5oz when she was born. But her length was measured in centimetres!

I am an engineer and design and build things in millimetres but there are still plans around my workplace which have chains and links to measure distance and use kips!! I have some feel for the size of a quarter acre block but measure things in hectares.

I think the 40 year frontier being suggested for adaptation is probably about right! because I'm not there yet!!!