Maybe the winner died before he or she could cash in. (Sad.)
Maybe the person lost the ticket or threw it away. (Unlucky.)
Maybe the person is from out of state and forgot. (Sad and unlucky!)
Or maybe the person has spent six months getting his or her affairs in order before claiming the jackpot. (Brilliant if a little obsessive.)
"I wish I had it," sighed resident Laura Winkles. "How could someone be so silly? This is just free money."
The owner of the Carrollwood Market said Monday that she wonders about the winner every day she walks into her store.
"The store is a neighborhood store, and pretty much 90 percent of our customers are regular customers," she said. "We still have a little bit of hope that somebody will come before Thursday."
(Read more: 'The drama isnonstop': Powerball winner wants old life back)
Nidia Tannous has placed signs in her store's window, urging customers to check their Powerball tickets from Memorial Day.
The store received $25,000 for selling the winning ticket.
"I bought a ticket that very day that ticket was sold here," said Joe Fitzgerald, a nearby resident. "I checked mine, and unfortunately, it wasn't mine."
According to the Florida Lottery website, if a Powerball jackpot isn't claimed within 180 days from the draw date, "the funds to pay the unclaimed jackpot will be returned to the lottery members in their proportion of sales for the jackpot rollover series."
In Florida, about 80 percent of that share will go toward the state's education enhancement trust fund. The remaining 20 percent goes to the Florida Lottery prize pool to fund new games and promotions.
(Read more: Know the odds: Being polite won't cost you lottery win)
For anyone who thinks they might have bought the winning ticket, here are the details:
It was purchased at Carrollwood Market on West Village Drive in Tampa. The drawing was Saturday, May 25, and the winning numbers were 02, 06, 19, 21, 27 and a Powerball of 25.
—By The Associated Press