The 47-year-old Spaniard defends the Alstom French Open this week with all too clear memories of last year's dramatic finish on the course.
Jimenez was two shots ahead with one to play, but dumped his eight-iron approach into the lake short of the green.
"We are human. I feel like I lose my rhythm - like the pressure is getting to me," he said.
His double-bogey six dropped him into a play-off with Francesco Molinari and Alejandro Canizares, but at the first extra hole Canizares put two balls in the water, Molinari bogeyed and Jimenez made a 15-foot par putt to become the oldest winner of continental Europe's oldest golf title.
It led to a fourth Ryder Cup appearance for the popular Malaga golfer, all but the first of them coming after his 40th birthday.
Jimenez thought Celtic Manor could well be his last match, but he has already had two runners-up finishes this season, losing only to Paul Casey in Bahrain and Lee Westwood in Korea.
Neither of them is in the field this week, but he does have to contend with world number four Martin Kaymer - winner two years ago - and big-hitting American left-hander Bubba Watson.
It will be the world number 12's first showing at a regular European event and he is seeking form two weeks ahead of The Open at Sandwich.
After two victories earlier in the season, Watson has not had a top-30 finish on his last five starts.
Colin Montgomerie, meanwhile, is among the players looking to qualify for The Open through a top-five finish on Sunday.
The last time Montgomerie finished that high in a tournament was on this very course three years ago, when he was runner-up to Pablo Larrazabal.
The Spaniard secured his Sandwich place on Sunday by winning the BMW International Open in Munich after a five-hole play-off with Sergio Garcia.