The Spaniard was left to stew for 21 days after the 3-0 humbling at the Amex last month - the first defeat of the season for the Premier League champions.
But the Gunners got that performance out of their system at the Emirates on Saturday, coming from behind to beat Leeds 2-1 thanks to goals from Riccardo Calafiori and substitute Bruno Guimaraes.
Arsenal boss Arteta, who signed a new contract this week, said his team had shown personality and courage to fight back against Daniel Farke's men, who had been unbeaten in the league before their trip to London.
"The last time that we put our shirts on, something was missing and we need to be very conscious of that - from being exceptional and being the champions to being extremely average like in that game is a really thin line," he said.
"So if you don't want it more than the opponent, you are not able to cope emotionally with certain situations, you're going to suffer, and we all suffered and we didn't enjoy one bit that game, but then you have to learn the lesson and we certainly have done that."
The Spaniard said he had struggled to come to terms with the Brighton defeat on the eve of a lengthy international break, which allowed Manchester City to move three points clear at the top of the Premier League.
"The first few days, week, not great, especially because you question yourself... but try to learn from it because otherwise you are starting to blame things," he added.
Arteta was asked how he would juggle his big squad, with forward Viktor Gyokeres starting on the bench on Saturday alongside Guimaraes, despite scoring four goals for Sweden in recent weeks.
"He will play games and he will have minutes and the best way is when they enter the pitch, show how good they are, that's it," he said, pointing out that Mikel Merino was also a substitute after scoring three goals for Spain during the international break.
Arsenal's win against Leeds took them to 15 points, behind Premier League leaders Manchester City on goal difference.
Enzo Maresca's City are in action against Liverpool at Anfield on Sunday.