dont we ever learn.

A titbit from history that seems rather pertinent nowadays.
On the 23rd of December 1865, France, Belgium, Italy and Switzerland formed the Latin Monetary Union and agreed to exchange their national currencies to a standard of 4.5 grams of silver or 0.290322 grams of gold (a fixed ratio of 15.5 to 1) and make them freely interchangeable. Spain and Greece joined in 1868, with Romania, Bulgaria, Venezuela, Serbia and San Marino joining in 1889.
The LMU was formed to facilitate the ease of trade between different countries by setting the standards by which gold and silver currency could be minted and exchanged.
By 1873, the price of silver had fallen substantially, causing the member states to abandon the bimetallism and make the Union a de facto gold standard.
Of course the LMU failed. Below are some of the events that transpired.
The LMU did not outlaw the printing of paper money based on the bimetallic currency. Italy and France printed banknotes to fund themselves, effectively passing some of this cost onto other union members.
Greece, due to its chronically weak economy, began decreasing the amount of gold in their coins, thereby debasing their currency relative to those of other LMU states. Greece was formerly expelled from the LMU in 1908.
As the price of silver was falling, Germany shamelessly profited from the situation. Germans went to Paris and Bruxelles with silver obtained from the recent demonetisation of thalers and transformed it into 5 franc coins which they converted for gold coins.
The United Kingdom, at one point, entered discussions with the LMU, however did not commit to join.
So what is different today? It would seem very little. Central bankers have learnt nothing, the Greeks still struggle, Italians are still living beyond their means and the Germans are still ruthless traders/arbitragers. At least the Swiss have learnt some lessons, albeit things that the Brits seemed to know intuitively.