The AC Milan attacker played against the Africans at the same stage of the tournament at the Sydney Games in 2000 in a game where Cameroon won despite finishing the match with nine men. Ronaldinho knows that Brazil should have wrapped the tie up and gone on to win the only major trophy to have eluded them.
"That day was very sad," said Ronaldinho who scored Brazil's only goal in that tie. "I hope that it will be different this time. It will be a special match because we are facing Cameroon and have the chance to qualify for the semi-finals."
The quarter-final eight years ago was staged at Brisbane's famous Gabba cricket ground. Patrick Mboma put Cameroon in front in the 17th minute before Ronaldinho levelled in the dying moments to send the match into extra-time where Modeste Mbami grabbed the winner with seven minutes left.
It was a great escape for the Africans who had both Geremi and Patrick Nguimbat red-carded. Cameroon made the most of their luck, going on to beat Chile 2-1 in the semi-finals with a last-minute goal and Spain in the final on a penalty shootout.
Ronaldinho, playing here as one of three permitted over-age players, believes the Olympics will also help him regain full fitness before his debut in Serie A with Milan, whom he has joined from Barcelona.
According to his national team coach, the 28-year-old player, having shed some excess weight, has rediscovered his love for the game. "Ronaldinho has found a way to smile again," said Dunga.
The man in the famous No10 shirt believes his greater experience over the eight years since the Sydney setback will stand him in good stead on Saturday. He is the team's unofficial counsellor, lending an ear to any troubles his teammates might face.
"We must respect Cameroon and not play with ideas of revenge," warned Ronaldinho. Dunga added: "I remember the defeat in Sydney as well as I remember our World Cup victory in 1994 in the United States."