And then you find out...you haven't.
Denmark's state lottery sent e-mails to 300 punters, congratulating them on their astronomical winnings.
However the messages were a mistake, with far too many zeros on the end. The real amount won by each punter would not even pay for a weekend away.
"It is amateurish to send out an e-mail like this," said one disappointed Dane, Flemming Dahl Jensen. "They mess with people's emotions, sending people on a rollercoaster. For someone with a heart condition, it could have been fatal."
The Danske Spil state lottery corrected the error, by e-mail, half an hour later. It blames human error for the blunder.
"We were about to start our new Eurojackpot lottery, with some very big prizes," said Danske Spil spokesman Thomas Roersig. "So we were adding zeros for internal testing and those zeros went out by mistake."
It is not exactly a riches to rags tale but Denmark's short-lived lottery billionaires have certainly come down to earth with a bump.