In the EU, when we had to change from national currencies to Euro, the outcry was big -- because everybody was only able to "measure" money in the old currency.

In the EU, when we had to change from national currencies to Euro, the outcry was big -- because everybody was only able to "measure" money in the old currency. That even exactly this currency changed over the past decades very much, seemed to be not in the minds. I guess, there are still people out there, which recalculate into Francs or Marks, or whatsoever -- but I think most Europeans have adapted. So, when "old Europe" can change -- why not "modern USA"?