Barcelona's Champions League winning team from the 2010/11 season is widely regarded as one of the greatest to play football.
Managed by Pep Guardiola and spearheaded by the likes of Lionel Messi, David Villa and Andres Iniesta, the Blaugrana utterly dominated European football.
And in the Champions League final, they tore Manchester United to pieces by beating them 3-1. Even Sir Alex Ferguson couldn't believe what he saw.
Speaking after the game at Wembley, he said: "They do mesmerise you with the way they pass it. I expected us to do better, particularly after half-time, but it wasn't to be.
"Great teams do go in cycles and they're at the peak of the cycle they're in at the moment. They're the best in Europe, no question about that.
"In my time as a manager, I would say they're the best team we've faced. Everyone acknowledges that and I accept that.
"It's not easy when you've been well beaten like that to think another way. No one has given us a hiding like that. It's a great moment for them. They deserve it."
Barcelona's side from six years ago had it all, with a solid defence, creative midfield and deadly attack constructed of Messi, Villa and Pedro.
Messi was undoubtedly Barca's best player back then - and he still is now - as Xavi would testify.
Xavi played alongside the Argentine wizard for 11 years and believes he is football's undisputed greatest ever player.
They haven't played together in two years and now Xavi has revealed a little known story about what annoys Messi most when he's on the pitch.
According to the Spaniard, Messi gets p***ed off if he doesn't touch the ball for longer than five minutes, both for Barcelona and Argentina.
"Barcelona and the Argentine national team cannot afford to allow 10 minutes to pass in a game without Leo Messi touching the ball," Xavi told Sport, per Goal.
"Messi has to be involved in the game. He has to be where things are happening, where the ball is. In addition, he's going to get p***ed off.
"If he doesn't touch the ball for five minutes, you have to bring him to where the ball is. He has to participate in the play."
Messi usually comes across as very calm on the football pitch, but Xavi claims he has an angry side that comes out when he's deprived of possession. Who knew.