Barca wrapped up their third consecutive league crown with two games still to play after an anxious 1-1 draw at Levante, making it nine trophies in three years since Guardiola took the helm at the Catalan club.
The 40-year-old coach shed tears on the pitch after the final whistle and kept repeating that it had been a particularly hard championship to win.
"The main difficulty this year was that it came after the World Cup and we didn't know how the players would react," Guardiola told reporters.
"Experience said we would fall," he continued, reminding everyone they needed to set a club record 99 points to win the title last season.
"But they kept it going. We proved they had the desire to keep winning and improving. They have taught us a lesson. Winning five leagues in seven years is something exceptional.
"These players are unique and the club's job will be to find fitting replacements as they keep getting older.
"Some areas have not worked so well and we need to strengthen in some areas. There are things we can improve."
Real Madrid's challenge under serial Barca-baiter Jose Mourinho pushed them to the limits, especially during the acrimonious four-match 'Clasico series', and their arch-rivals beat them 1-0 to win the King's Cup Final last month.
"Now is the time to celebrate because the league is an important title," the Spanish international told the club website.
"Afterwards we can rest and prepare for the final at Wembley."
