Fantasy project #2. Inch vs Metric.
This one might be arrogance at it's ultimate economic cost. Strangely enough it's the American's on one side and the rest of the world on the other again. A big compromise at the time would have solved this problem by now at a huge benefit to both sides. In the real world outside of the arrogant bickering it would have fixed things right away. My fantasy fix would have been to make one meter exactly eight feet long. For anyone who can reason, spend a day or two doing the math and have the lights come on. The excitement will build as you start to get it. Find what the spread between an inch and a Centimeter would be. The biggest thing to consider. It's never to late to correct a fundamental error. Gold is next.