Talking to Football Daily, the City boss said: 'That's why it is so hard to win it.
After his unprecedented success in Spain with FC Barcelona, many wondered if the Spaniard would be able to replicate that glory elsewhere, perhaps at a club with less talented players, and less resources, with some even dubbing him "Fraudiola". I know the people say "You are good" or "You're not good enough". "I never ever really felt I am the best, never ever in my life".
Guardiola also spoke about the Premier League's runaway leaders, world champions and defending European champions, Liverpool, who he hailed as the best team on the planet.
"Liverpool spent four or five years to win their first trophy last season", he added.
City meet Los Blancos in the last 16 of the Champions League, and the Premier League champions are struggling this season compared to last, while Real Madrid are top of LaLiga Santander. New gamers, financial investment, an increasing number of, as well as after they obtained them they are the best group in the globe now.
He is now considering success in the Champions League, with the very first leg of their last-16 connection with Real Madrid readied to be used February 26 at Santiago Bernabeu.
Sometimes there are opponents, sometimes you can not do it because in no sport does one team win all the titles all the time. "Not all the time in any sport has a team won everything every season all of the time". Or maybe he will say "OK you've done well, but what can we improve?"
"But if we do not defeat Real Madrid, then Man City's Chairman or Sporting Director will say to me; "We did not do well, we wanted to win the UEFA Champions League, and now I am going to sack you from your post".
"And this process, the two weeks before, will be the happiest moments of my profession, to imagine what we can do to beat them".