Messi’s side’s loss two seasons ago was the biggest margin of defeat in the history of the Champions League semi-finals, and the Spanish giants will be looking to exact revenge as the two sides meet again on Wednesday.
"That hurt a lot, but a lot of time has passed," said the Argentina forward.
"We come into the game differently, as do they, and it will be a different tie to that one."
Bayern Munich coach Pep Guardiola, who spent four years in Catalunya as the boss of Barca, winning three league titles and two Champions Leagues, was in charge of the Blaugrana for that result but has since joined the Germans.
Guardiola has secured the league title in both his seasons in Bavaria will visit the Nou Camp for the first time as he takes Bayern to Spain for the first leg of their semi-final tie.
Pep Guardiola - Lionel Messi
Image credit: Reuters
Messi, who will make his 100th European appearance on Wednesday, said: "He was with us for a long time and we had the luck to win many titles and experience important moments. He is a coach that studies everything.
"It is the same for both sides. Pep knows us very well and we know what he asks of his players. It is 50-50, we both know each other very well."
Barca midfielder Andres Iniesta said: "We experienced some really great moments together. Wednesday's game will be special for everyone because the memories are always there."