Bulgaria - the poorest country in the European Union - has become the 21st member of the eurozone - leapfrogging more obvious and prosperous candidates like Poland, the Czech Republic and Hungary.
For mostly urban, young and entrepreneurial Bulgarians, it's an optimistic and potentially lucrative leap - the final move in a game which has brought Bulgaria into the European mainstream - from Nato and EU membership, to joining the Schengen zone, and now the euro.
For the older, rural, more conservative parts of the population, the replacement of the Bulgarian lev by the euro provokes fear and resentment.
The lev - meaning lion - has been the Bulgarian currency since 1881, but it has been pegged to other European currencies since 1997 - first the Deutschmark, then the euro.
Opinion polls put Bulgaria's 6.5 million population more or less equally divided on the new currency, and political turmoil is not making the transition easy.
Prime Minister Rosen Zhelyazkov's coalition government lost a confidence vote on 11 December, after mass protests against the 2026 budget. Bulgaria has held seven elections in the past four years - an eighth looks likely early next year.
"I don't want the euro, and I don't like the way it has been imposed on us," Todor, 50, a small business owner in the central town of Gabrovo, at the foot of the Balkan mountains, told the BBC.
"If there were a referendum, I reckon 70% of the people would vote against it."
A referendum on euro adoption was proposed by President Rumen Radev but rejected by the outgoing government.
Todor's business, producing coloured plastics for the domestic market, had a bad year because of high inflation, he said, and a fall in sales fuelled, he believed, by fear of the euro.
Ognian Enev, 60, who owns a tea shop in central Sofia, was more enthusiastic. "On the whole, it's a good thing. It's just a technical change. It doesn't bother me," he told the BBC.
In any case, he pointed out, people who bought flats or cars until now have got used to prices marked in euros. The 1.2 million Bulgarians who live outside the country have also been sending money home for years in euros.
Like many shopkeepers, Ognian has the new currency ready, in coins and small denomination notes, ready for the transition.
Throughout January, you can pay in both lev and euros, but change is supposed to be in euros. From 1 February, it will no longer be permitted to pay in lev.
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