Jason Day suffered a bizarre memory lapse ahead of the WGC-Dell Technologies Match Play when he had to be reminded that he won the event in 2014.
Day is back in Austin, Texas as defending champion having defied a back problem last year to claim his second PGA Tour title of the season, just a week after collecting his first at the Arnold Palmer Invitational.
The Australian edged out 2015 winner Rory McIlroy in a high-quality semi-final before thrashing Louis Oosthuizen 5&4 to emulate his victory of two years earlier, when the tournament was still a straight knockout and staged at Dove Mountain in Arizona.
On that occasion, Day pulled off a thrilling win over Victor Dubuisson in the final which went to the fifth extra hole as the Frenchman kept himself in the hunt with some outrageous escapes from the desert scrub.
But despite coming out on top in one of the most memorable finals in the tournament's history, Day had clean forgotten his achievement as he fielded questions at his press conference.
"Who won it the year before Rory?" he asked the assembled media, only to look surprised when a journalist answered: "You did!"
"I did? Okay," added Day amid much laughter in the media centre. "I had no idea, that's terrible man, that's shocking!"
Day prompted further laughter when he could not recall how many rounds he played that week, saying: "I can't remember what the old format was, how many rounds it was. Do you know? How many rounds was it with the old format? Was it six rounds? Seven rounds ... I can't believe I don't know this stuff."
The 29-year-old has been drawn in the same group as his compatriot and good friend Marc Leishman, who arrives in Texas full of confidence having clinched his second PGA Tour title at the Arnold Palmer Invitational last week.
The pair face off in the final group stage match on Friday, but Day admitted that friendship would be put to one side while on the course.
He said: "Marc is a good buddy of mine, as most of the other guys are too. I played Louis, who is a close buddy, last year in the finals and obviously Rory in the semis. Everyone knows each other, but some guys you're closer to than others.
"But when it comes time to play match play you've just got to go out and try and beat them. You're not really friends for 18 holes and then when you get off the course you're back to being mates.
"So it's tough because this format you have to think differently In stroke play you're playing 72 holes and you've got time, you can be patient. But in this kind of a format, it's kind of cut throat where you have to perform right now, make the birdies and get it done with."