Grant Holt scored the winning goal at Carrow Road to condemn the Gunners to their second defeat of the season.
Wenger admitted that his team were lacklustre but backed his squad to respond positively over the next few games.
He told the club's official website: "I hope it will have a positive impact. It was a shock to the system today. But you have to give credit to Norwich today.
"Maybe we underrated the difficulty we would face but if you are not ready for the fight then you will always have bad surprises.
"There is a big difference between the amount of possession we had and the amount of chances we created. That is down to the fact that Norwich defended well and we did not create a lot."
The Gunners are back in action on Wednesday in the Champions League against in-form Bundesliga side Schalke.