Guardiola won the Champions League twice in three years while in charge at Camp Nou, but was unable to repeat the feat in three years at Bayern Munich, and is currently on his third attempt at winning it with Manchester City.
During a press conference held before City face Schalke in the last 16 on Wednesday, a reporter told the Catalan that he and his achievements are the centre of a "massive argument on Nigerian Twitter space".
It was put to the City boss that his online detractors argue that he "has not been able to win the Champions League since leaving Barcelona" as he "does not have players like Messi, Xavi and Iniesta."
Guardiola smiled and replied: "I completely agree with them. Completely agree with them. I would not argue for one second becuase when I was there I said many times that I had incredible players.
"I did as well with Munich and Manchester but in Barcelona I was a lucky guy, I'm sorry, I was lucky. I agree with them."
Guardiola guided Barca to the Champions League in 2009, his first season as a coach, and again in 2011, beating Manchester United on both occasions. The Catalan club have gone on to win it once more since he left, in 2015.
His Bayern side, who were reigning European champions when he took over from Jupp Heynckes, were only able to reach the semi-finals during Guardiola's time in Munich.
Speaking earlier in the press conference, Guardiola addressed that defeat in Monaco in his first season, referring to City's elimination that year as a "big fail", which was almost certainly a sarcastic comment aimed at those who expected his side to have done better.
"Yeah but the first season was a big fail because we were not able to win the Champions League, it was the first season," he said, before insisting that his side are better equipped this time around. "We are together a lot of training sessions, a lot of games, a lot of meetings, we know each other better now.
"This competition is special, the teams are good, with the atmosphere in the stadiums you have to control the emotions, you have to suffer the bad moments, survive the bad moments and in the right moments make the difference.
"But we are confident. We arrive with many dreams in our heads to make a good game and to bring the game in a good position back to our stadium, where we are very strong, we feel confident there. We have to make a good game and of course to try to score goals, it's important to score minimum one goal."