A majority of Germans were unhappy to be giving up Deutschmarks for euros, with 39 percent indicating they are happy to be making the exchange.
Men would turn up with holdalls and shoeboxes piled with notes and turn them into Dutch guilders, Deutschmarks or, latterly, euros.
The agreement came about very much on German initiative, because the Germans were fearful about abolishing the Deutschmark in favour of a European currency.
Funds flowed back into the Deutschmark from the dollar, and funds leaving the French franc were also converted into Deutschmarks.
From the whole euro zone perspective, Germany has the most to lose because the Deutschmark was the strongest of all currencies going into the single currency conversion in the late 1990s, a financial analyst says.
Indeed, acceptance of it was said to be Germany's price for giving up the much-treasured Deutschmark in the first place.
This is partly because the Deutschmark joined the euro at too high an exchange rate.
The State Treaty would introduce the Deutschmark as legal tender in East Germany, while the Unity Treaty was about introducing West Germany's political and legal system in the east.
Much of the earlier strong performance of the Dutch economy was due to a decision in the early 1980s to link the guilder to the Deutschmark through the European Exchange Rate Mechanism.
Germany's euro conversion rate may be one of the easiest - almost exactly two Deutschmarks to one euro.