Ben Pridmore from Britain once again has proven he's got the most powerful memory in the world.
The three time international champion faced down stiff competition in events that included matching names to faces and memorizing 4,000 numbers in sequence.
They call themselves mental athletes but most admit - proudly - they're also nerds.
The contestants rely on a combination of unshakeable concentration and sound technique.
"If it's a string of numbers, I see those numbers and I have pictures that correspond to every number," said Ronnie White, a memory competitor from Texas.
White says that long strings of numbers are more memorable if he makes them into mini-stories.
"Today I had Mickey Mouse swinging on a rope into a medical student," White said.
White, an Afghanistan veteran, won the U.S. championship last spring. But in London, suffering from jet lag, he just wasn't a match for his opponents, male or - much rarer - female.
"I'll tell you what. Dorothea from Germany over there - the woman - kicking my butt," White said.
Dorothea, who is only 17 years old, finished in the top ten. But she's got her eye on fierce and growing competition from China which fielded a big team this year - the only ones with matching tracksuits.
"They are, really have a good team. It's kind of intimidating," said one competitor.
Intimidating is also the word for Ben Pridmore who memorized a whole deck of cards in just over half a minute to clinch his win today.
"The standard just keeps getting higher at these competitions," Pridmore said.
But there's constant pressure to improve. Every year the scores get higher and higher. So the on thing these competitors can forget is any thought of slacking off this winter.