Chelsea boss Jose Mourinho is still haunted by the Anfield "ghost goal" as he prepares for the first leg of the League Cup semi-final against Liverpool on Tuesday.
Ten years after Luis Garcia's controversial late winner at Anfield sealed Chelsea's fate in the 2005 Champions League semi-final, Mourinho has another chance to banish the demons.
"I have difficult memories from there," the Portuguese said. "To lose a Champions League semi-final with a goal that is not a goal stays forever. You don't forget it."
Television replays suggested Garcia's bundled effort did not cross the line and Chelsea went home feeling robbed while Liverpool went on to win the Champions League.
"In the League Cup there is no goalline technology," Mourinho added.
The Chelsea manager suffered another gut-wrenching Champions League semi-final defeat by Liverpool two years later, this time on penalties, but he has also enjoyed happier moments.
The Anfield club were the opposition in the 2005 League Cup final when Chelsea won 3-2 to deliver the first of the five trophies Mourinho claimed in his first spell in charge at Stamford Bridge.
Then there was last season's Premier League clash at Anfield, his first season back at the helm for a second stint.
On that occasion, a a terrible mistake by Liverpool captain Steven Gerrard paved the way for Chelsea's 2-0 win, effectively scuppering the home team's dream of winning the title.
Chelsea fans enjoyed reminding Gerrard of that mistake during a 2-1 victory at Liverpool in November but Mourinho, who once tried to sign the midfielder, hopes they will spare the former England captain similar treatment.
"The song that my fans have I don't like at all," Mourinho said. "A couple of times is good fun but to go and go, especially with a player like him who deserves respect, I don't think you need that."