The Italian failed to guide the Ligue 1 outfit to the title after taking the reins from Antoine Kombouare in the 2011-12 winter break, as PSG finished second behind Montpellier.
However, the title did not elude the capital club in Ancelotti's first full season at the Parc des Princes and the 54-year-old believes that that was a key triumph, arguing that PSG have now become even stronger mentally under Laurent Blanc, who is poised to lead the Parisiens to a second successive title.
"We didn't have a real identity to our play in that first season," the current Real Madrid coach told the official Ligue 1 website.
"That wasn't true of the second season, especially the second half of the second season. In the Champions League we only narrowly lost out to Barcelona.
"I felt respected in France; it was just difficult to change the working mentality when I arrived.
"We needed to change that in order to fulfil the ambitious objectives set out by the Qataris (Qatar Investment Authority, owners of the club), in order that Paris became a team in accordance with the financial potential of the club.
"I think Paris has improved a lot on this front and now PSG has that winning mentality."
PSG currently sit eight points clear of second-placed Monaco and can wrap up the Ligue 1 title with a home victory over Rennes on May 7.