Maria Carreiro, a 51-year-old from Toronto, was delighted when she checked her lottery ticket at the store the day after the draw and thought that she'd won 40,000 Canadian dollars (which is worth around £26,000). She rushed home to tell her family about the win, when she discovered she had made a mistake.
She hadn't won $40,000: she had won $40 million.
ShockThe Canadian grandmother told a press conference that she "ran down the street like a crazy woman" after she checked the numbers online again with her daughter and realised the true size of her winnings.
Her enthusiastic celebrations didn't end there, and according to Yahoo, at the lottery-cheque presentation she danced, blew air kisses and said " Thank you Lord, Thank you Lord, I love you!"
Her early spending had been somewhat modest - as she took the family to a Manderin all-you-can-eat buffet. However, she said she planned to spend some of the money on taking a honeymoon to Hawaii - 30 years after her wedding, and on moving to a larger house. She will also share the winnings with her three children and five grandchildren. Her husband Mario has quit his two jobs.
It's a heart-warming tale, and her mistake turned out to be just another stroke of good fortune for this lottery winner.
Lucky mistakesShe is not the only lottery winner to have made a lucky mistake. In December last year Scott Bennett, a 48-year-old from New Hampshire in the US won $1.3 million by accident on the Megabucks lottery. He had gone into the shop intending to buy one ticket for the Tri-State Megabucks lottery and one Lucky for Life ticket. However, the store assistant accidentally sold him two for the Megabucks - the accidental one was the eventual winner.
A similar lucky mistake hit Richard Brown of Taunton - just south of Boston - who got a different scratchcard to the one he had requested last August. He stuck with the one he had been given and won $650,000.
And in Ireland there were 18,000 particularly lucky winners in January this year, when the National Lottery there misprinted the number 9 as a 6 on one of the balls, and the organisers had to pay out for both combinations. It said the mistake would cost them 54,000 euros.
Not so luckyBut mistakes don't always work in your favour when it comes to the lottery. Back in Canada in 2009, Ontario's gaming officials accidentally printed 1,100 winning scratchcards which weren't supposed to win. Between 50 and 150 of them were purchased, with one punter thinking he must be really lucky, because he had won on each of four scratchcards and was set to net $135,000. In the end he was entitled to nothing.
Most of us walk away from playing the lottery feeling a bit unlucky - but clearly it could be much worse!
- Lottery winner blows £1.8m: unlucky or daft?
- How to win more from the lottery
- Winning Lottery syndicate row over members who didn't pay