Just three years ago, the euro was being praised as the can-do currency that had delivered unprecedented prosperity in Europe.
Now, it's widely derided as a hugely flawed experiment in the wake of a debt crisis that's threatening its very existence -- an uncomfortable backdrop as the currency's notes and coins hit their first decade in circulation Jan. 1.
The question is: Will it get to its 11th birthday, let alone 20th? In the euro's tumultuous short history, it has already been heralded as the ultimate mark of a peaceful, united Europe; scoffed at as a giant act of hubris by a distant political elite; and credited with giving Europe a more influential voice in the world.
These days, as it faces its biggest crisis yet, the euro is a daily reminder to more than 330 million people of the dismal state of the economy in the 17-nation eurozone. Many countries seem headed back into recession, and policymakers are grappling with a spiraling debt crisis.
While few Europeans are prepared to scrap the euro -- in part because they fear a chaotic collapse more than the current muddle -- some are nostalgic for the money they counted on before it arrived.
Parisians waiting to exchange their old francs outside a branch of the Banque de France before a Feb. 17 deadline harked back to the "rosy" days.
"Life was better before," said Mamia Zenak, a 52-year-old doctor. "[The euro] is a misery for everyone."
But it was not always so.
In 2009, fanfare accompanied the 10th anniversary of the euro's "launch," when it began floating on international exchanges and banks and governments started using it in their accounting. It was widely credited with briefly cushioning the countries that use it from the banking crisis sparked by the collapse of U.S. investment bank Lehman Brothers in 2008 and for preventing proud euro member Ireland from descending into the economic chaos that befell non-euro Iceland.
"When the euro was launched, there were plenty of people who thought it would crash and burn," the BBC wrote in a story on its website at the time. "Ten years on, its role as a global currency is secure."
It doesn't look so secure now. Events took a dark turn in 2010, when the debt-fueled boom years finally caught up with Greece and the eurozone realized it couldn't deal with its economic implosion.
Now as 2012 dawns, the euro's role as even a regional currency is uncertain as the crisis has spread to much-bigger Italy, with many skeptical about its ability to survive, at least in its present form.
Once seen as a sign that eastern European countries had "made it," joining the euro is now a far more sensitive subject. Poland, for one, is carefully measuring its words, calling for reforms before it joins.