Barcelona coach Luis Enrique said his players would learn from the experience after their shock 2-1 Clasico defeat at the Camp Nou on Saturday.
Barca went into the game 39 games unbeaten in all competitions, 10 points ahead of Madrid in the table, and widely expected to repeat last season's Treble of La Liga, Champions League and the Copa del Rey.
An emotional night which featured a moving pregame tribute to late Blaugrana legend Johan Cruyff seemed to be going to plan when Gerard Pique headed the home side in front near the hour mark.
But Zinedine Zidane's side showed unexpected resilience and hit back with counter-attack goals from Karim Benzema and Cristiano Ronaldo, and held on for the victory even when Blancos captain Sergio Ramos was red carded.
The Blaugrana coach told his postgame news conference that his team had been taught that they could let slip what had seemed to be a commanding position in the game.
"Losses can teach you that all trophies are difficult to win," Luis Enrique said. "The players know how difficult any game can be, even more against an opponent who has the same objectives as you.
"What happened to us can happen in any game. We managed most of the game, created many chances, had a very good first half. But it was dangerous situation, as in the transitions we suffered in the last 15 minutes.
"It is painful to lose at home; had to happen some day. But we must move on, prepare for the Champions League, and it will be a very difficult game. We are still leading in La Liga, and we must keep pushing forward."
Luis Enrique accepted his team had not defended well in the final quarter-hour of the game, when they were regularly caught on the break, but denied his substitution of Ivan Rakitic for Arda Turan had been to blame.
"If you have many players ahead of the ball, then you can suffer in transitions," he said. "You cannot always be well positioned to watch that.
"We had most of the possession today but football is difficult, capricious, and they caught us on the break a few times, in last 10 or 15 minutes, when we did not have control of the game.
"Ivan had a [yellow] card, and there was a risk [of another]. Arda could bring us more play between the lines. He had bad luck as came in just as the game got a bit crazy. But this is a sport where errors happen, and we must accept that."
Asked whether he felt referee Alejandro Hernandez Hernandez, just 33 and in his first Clasico, had erred in not sending off Ramos much earlier in the game, Luis Enrique said he accepted the officials had a tough task.
"I do not usually talk about referees," he said. "These tense games are difficult for the players, and for the referees too."
Many of Barca's players, including their superstar South American front three, travelling extensively during the recent international break was not an excuse either.
"I do not have to talk about that, as I do not like to look for excuses when result not good," Luis Enrique said. "Over the season the team has to play after international breaks. We have the world's best players, they will travel, and we must accept these circumstances."
Luis Enrique accepted.It was a pity that Cruyff's passing was not marked with a win for Barca's cule fans.
"We would have liked a different result, but football is curious like this," he said. "We must get up quickly and lift the players. We gave everything, the fans were great as always. There is nothing else to do than get up again.
"Today did not go as we expected, we wanted to give joy to all cules. But this is difficult as we play against rivals with quality."
The Asturian added that he was already focused on Tuesday's Champions League quarterfinal first leg at home against Atletico.
"This game does not exist for me any more," Luis Enrique said. "What is still to come is very important. We can focus on things we have been doing well, improve what can be improved.
"Atletico will be very difficult rival, they defend very well, and they want to continue in the Champions League just like us."