In case you didn't hear, the sole winner of last week's $400 MILLION Powerball jackpot came forward yesterday.  Here's what we know about him . . .

He's from Columbia, South Carolina, and he wants to remain anonymous.  And he's lucky he can.  Only South Carolina, Delaware, Kansas, Maryland, North Dakota, and Ohio let Powerball winners stay anonymous.

A few hours before the drawing last Wednesday, he went to a convenience store called Murphy's Express . . . to buy his wife some HOT DOG BUNS for dinner.  But the store didn't have them.  So he decided to spend the $20 bill he had on lottery tickets.

It was only the second time he'd ever bought lottery tickets in his LIFE . . . and he didn't realize he'd won until he checked his ticket the next day.  He said the first person he told was the family dog as he redeemed the prize yesterday.

The full jackpot was actually $399.4 million.  It's the fourth-largest in Powerball history, and lottery officials didn't say if he took the lump sum of $233 million, or the annual payouts.