The Belgians raced to a two-goal lead in their Champions League opener on Wednesday night, but the scoreline did not put the Gunners on the back foot, rather spurring them on to complete a remarkable comeback.
“We were caught cold by a team who were really ready and started out of the blocks at full power," said Wenger.
"Standard played like it was a cup final with full commitment.
"When you go 2-0 down after five minutes, you know you have a big task in front of you.
"To win away from home in the Champions League and score three goals will be tough.
"You have to attack with full power, without restriction, and know that the next goal will kill you.
"We fought back with a goal and then in the second half, the game dropped a bit in physical intensity.
"When they got tired, we got set-pieces and took advantage of it.
"It can happen to anybody and you have to be strong."
Wenger added: "When you are at a big club, you cannot afford to have too many defeats on the trot.
"After being 2-0 down, this will strengthen belief within the group."