City had been touted as potential 'Invincibles' this season following a record-breaking start to the campaign, but they saw a 30-match unbeaten league streak come to an end at Anfield in a seven-goal thriller.
The league leaders - who still enjoy a 15-point advantage at the top of the table - almost rescued their run with a late comeback but ultimately fell short as Liverpool held on for all three points.
"Our first defeat. The bad news is we lost so congratulations to Liverpool for their performance. We knew what a good team they are. We were not precise with the ball and started with problems but we recovered as well. The only action we had then we conceded a goal, and then we lost a bit of control. We were not as stable. Then after that it was difficult as we conceded too many goals in five or 10 minutes," Guardiola told BBC Sport.
"We tried and now we recover. People asked if everything was over and done before Christmas and now it's January and it's not. We have a lot of games to win to be Champions and will try for the next game against Newcastle. We have to learn. We have a young team in many places. We conceded a goal from Firmino when we were the better side but they can punish you when you make a mistake. They have the quality to run and make fast counter-attacks.
"We've won a lot of games in the last minute but to concede four goals is not good. You have to live this type of situation during a season. I've won a lot of titles and always I've dropped points and lost games. It's normal. Every team fights for the Champions League, to win the league or to stay up. We have a lot of games and hopefully we can stay fit in the schedule of games every three days. But to lose a game is absolutely normal."
City will now look to return to winning ways when they host Newcastle United next Saturday.