The Bavarian giants strolled to the Bundesliga title last season, wrapping it up with six games to go and by an eventual margin of 25 points.
They also became the first German team to win the league, cup and European treble, but Guardiola said that his ideas will take time to put into practice.
"It's not easy always having to win," Guardiola told reporters. "People believe we'll win six or seven nil, but that's just not possible.
"The supporters want more and more and more, but I have only been with the team for six to seven weeks, I need more time.
"I'm just a normal coach, I'm not some super trainer."
Guardiola replaces Jupp Heynckes at Bayern after a year-long sabbatical.