Ahead of Saturday's match against fellow first-round losers Adelaide, Brown said the loss might prove a blessing in disguise.
He said they had already "sparked up" at training.
Following their triumph in the NAB Cup just two weeks earlier, the Lions were heavily fancied to beat the Bulldogs, but returned to Brisbane with a 68-point loss behind them.
Brown said they had trained poorly in the lead-up to the Bulldogs clash.
"It's round one and we had a shocker, but there's still 21 games in the season to go," Brown said.
"It was the basics of the game, not structures or selections, it was us players on the field that didn't bring that competitive spirit to the game.
"We're certainly not relaxed about the situation, disappointed with what happened last Saturday, but we've got to keep it in perspective.
"[We had a] terrific end to last season, terrific pre-season, you don't lose your form overnight. We've just got to bring our intensity levels this week."
Brown said the only positive of a round one hiding was the Lions had plenty of time to regroup and right the season.
In good news for the club, ruckman Matthew Leuenberger got through a full reserves match to put his hand up for senior selection and Pearce Hanley accepted an early guilty plea for rough conduct against Daniel Giansiracusa and will play against the Crows.
Brown said Adelaide would be a stern examination, but hoped the likely hot and humid conditions with a 3.40pm start would suit the home team.
"They finished second last year; we had a strong game against them last year at the Gabba where we beat them (by 10 points in round 21) so we've got some confidence against them," he said.
"They're a top four team from last year, they're a terrific team, they'll be hurting after losing round one.
"You need to have early season form to get anything out of the season. We don't want to be zip and two after the weekend."
