Farrell Treacy made a mistake he says he has "never done before" which cost him a chance to compete for a medal at the Winter Olympics.
The Team GB speed skater was hoping to make it through his 1000m heat on Saturday, but made a fatal error which cost him the chance to make it through to the next round.
Explaining why he had not managed to make it through the heat, Treacy explained that he thought he had heard the bell on the penultimate lap.
Because of that, he sprinted for the line too early and his time suffered for it.
"I swear I heard a bell and I went to the line a lap early, which is obviously excruciating in the position I was in," he told BBC Sport.
It was, as Treacy himself admitted, "a big mistake".
"I don't know if there was a noise, I just assumed there was a lap to go in my head," he added.
"It was like this was the last corner and then really late when I was lunging for the line, I heard the bell then and I was like 'oh my God, what's happened?'
"It's my fault. I've never done this before so it's not a great time to do it, at the Olympic Games."
Treacy woes were part of a wretched day for British athletes on the skating rink.
His younger brother Niall, who had been skating in the previous heat, had crashed out of the competition on the back straight.
"Going on the ice meant I became an Olympian, which is something I have always dreamed of," the 21-year-old said as he tried to see the bright side.
"Unfortunately it didn't play out the way I planned it to. Last-lap heartbreak there, but I proved to myself that we should be here, we're in the mix with the world's best.
"It was a shame about that little mistake at the end."
Meanwhile, in the women's 500m event, Kathryn Thomson got her Games off to the worst possible start by falling on the exit of the first corner.
"I don't think I made 15 seconds before I hit the ice, that's really frustrating as I was looking forward to that race," the frustrated skater said after the action.
"I got a really good start but then I felt hands on my legs and the next thing I was on the ground. I'm a bit annoyed that the officials didn't call us back but I need to review that.
"I was hoping to build on my events through the Games but I've still got two really good opportunities to see what I can do."
