Lyon's three-game unbeaten league run came to an abrupt end in the French capital at the weekend to leave Garde's men 10th in Ligue 1.
Garde is now keen for his players to bounce back with victory over Toulouse on Thursday.
"We have to turn the page, we have a busy schedule," the Lyon coach told the club's official website. "A defeat is never something that can be just forgotten about.
"The heavy defeat reminds us how much of a difference there is between the sides, we an't just brush it under the carpet.
"There are a lot of important matches for us coming up in the league."
The 47-year-old also called on his side to show more character and not let their heads drop when they fall behind in games.
"The loss to Paris is also due to a certain lack of character," he added. "We have to be more mature.
"When things don't go our way, we have a tendency to drop our heads, individually and collectively.
"It's a fact. I'm not having a go at my team. This defeat shouldn't change anything.
"It only shows us how much work we have to do."
