It's the last artifact of a physical object used to measure all others. And that fucker changes weight too, so the kilogram ISNT stable. Its just like all those nasty imperial measurements used to be.
Does that make sense?
But, if the rest of the world is to ask of the US to switch to the metric system, there will be a time when the authorities have to enforce the system onto the citizen.
Sometimes, the greater good of the community does not align with that of the citizen. We Europeans have switched from our country's respective currency to the Euro not to please us personally but for the economic good of the whole European Union. (Whether it has succeeded or not is another debate altogether.) It sure wasn't easy for the ol' timers, but now it's all behind and even my parents don't think back in Francs when they have to pay their baguette and wine.
The behind-the-scenes motivation wasn't about the common good, it was about the French trying to gain formal influence on monetary policy. The Germans had to agree in exchange for the French consent to German reunification. (Before the Euro, the rest of Europe was more or less reduced to copying German monetary policy, or face devaluations.)
No really, the worst thing that ever happened to metric system conversion was getting endorsed by the UN. That was the kiss of death. We created the UN, we host the UN, we fund the UN, and we hate the UN. Anything backed by the UN gets turned into the UN trying to take over the US and creating a new world order.
And after the debacle with the, UN-based, ITU trying to take over internet governance metric will never get a serious political foothold in the US.
But at least food labels are all metric.
Would indicate that the process has being going on for some 40 years and is still not at all complete. That to me indicates that it's not "easy" either.
Just with the Euro the change should be at once. Then everybody will be fine in 2 years or so.
I'm telling it like I see it, please do not ascribe malice to what I'm writing. I wish we had the metric system in the US, but the units just aren't as meaningful as familiar degrees F, pounds, inches, feet, miles, and so on. That's true for me even after having spent a lot of time living here in Italy, to varying degrees, depending on how much I use a given unit.
Do you remember the transition to the Euro? How you had to mentally convert prices at first? And how old people had more difficulties with it in some cases? Now, imagine that, not just for one unit, but weights, lengths, temperatures and volumes, all at the same time.