The Germans qualified top of their group with 10 wins from 10 games and also scored confidence-boosting victories over top teams including Brazil, Uruguay and Netherlands in friendlies last year as talk of their first title since 1996 grew louder.
Wednesday's defeat against France, who less than two years ago spectacularly flopped at the World Cup in South Africa, was a sobering experience for Joachim Low's team, highlighting the fact that it may not be plain sailing for them in Poland and Ukraine in June and July.
"We should complain because we could have conceded one or two more goals," said Germany's Thomas Muller. "While we should not read too much into this result, we were not very disciplined in defence.
"We were too open at the back, we worked too little and left our defence without backup," said the 2010 World Cup top scorer.
Germany were missing injured captain Philipp Lahm at the back as well as central defender Per Mertesacker.
In midfield, Bastian Schweinsteiger - nicknamed "the brain" by Low - was also out injured, as were Mario Gotze and Lukas Podolski.
It was not, however, the first time Germany had taken to the pitch without key players and throughout the game they were on the back foot against the speedy French, who played the sort of quick passing and attacking game that has made Low's team one of the most exciting to watch in the past two years.
Low said it was a deserved win for France but his team, who have two more friendlies against Switzerland and Israel, would bounce back in time for the Euros.
"We are obviously a bit annoyed with the result but I am more annoyed about the way we lost," the coach told reporters. "But we must keep in mind it was a long break since November, there were some changes, some injuries and you can lose your rhythm a bit.
"Once we are together for three or four weeks it will be much better."
Central defender Mats Hummels shared his coach's view, saying: "If all the players are back then we have an outstanding team."
