It took only one-hundredth of a second last year to completely sap the confidence of Australia's star swimmer James Magnussen.
Suddenly, the positive mental approach that had been his biggest asset had dissolved in the water at London's Olympic pool.
His loss by the narrowest margin to American Nathan Adrian in his pet 100m freestyle event was shattering.
For weeks afterwards, he struggled to see a future in the sport he had always loved.
But, in one of the few interviews he has given since returning from the Olympics, Magnussen has told _The Weekend West _ how a sports psychologist - or "mind coach" as he calls him - has turned his head around and fuelled his fire for more swimming success.
Magnussen - the "Missile" - has returned to the pool and his training "has gone to another level", according to coach Brant Best.
Every morning he swims three hours, spends an hour in the gymnasium and sees a physiotherapist each afternoon.
His sights are firmly set on defending his 100m freestyle title at the world championships in Barcelona in July. The first step towards this goal will be a good performance in the world's richest swimming event - the inaugural Aquatic Super Series in Perth next weekend.
Magnussen is part of a 30-member Australian team that will take on swimmers from China and South Africa for a share of $500,000.
Magnussen admits he had huge expectations going into the Olympics. The Port Macquarie-born swimmer was favoured to win two gold medals but was edged out in the 100m and missed a medal altogether in the freestyle relay.
When he touched the wall at the end of the 100m final, he didn't know if he'd won or lost. But he knew he hadn't swum to the best of his ability.
To add to his disappointment, he was criticised for slumping into a chair while his teammates were still swimming in the relay final and was embroiled in a controversy surrounding the behaviour of the relay team at a training camp in Manchester.
He admits he made mistakes - and he intends to learn from them. "I know I put too much pressure on myself - I had huge expectations," Magnussen said. "I took a big hit mentally at the Olympics. I lost my confidence - and my confidence has always been one of my strengths.
"I realise now that I needed more balance between enjoying the sport and achieving success.
"Everything happens for a reason and the disappointments of London have definitely motivated me to become a better swimmer."
Magnussen has made several changes to his approach, including his training regime, and has begun using the sports psychologist.
"The mind coach is not only helping me with my swimming but also my approach to life in general," he said.
"It has been very helpful and given me a better understanding of my sport and myself.
"It's put the fun back into swimming."
He has also established a tight-knit support group, including his coaches and management team, that has helped him through the tough times and allowed him to refocus on his swimming ambitions.
"I am looking forward to Perth - to getting back in the pool and back into competitive swimming," he said.
"And it's going to be in front of a home crowd, which will be great."