The 23-year-old Poland international was replaced by Lukasz Fabianski in March after a poor run of form, but insists this time out has made him a better player.
Szczesny was left out of four matches but has started every game this season and attributes his return to form to the disappointment of being dropped.
"Obviously I had mixed feelings about my form last season, I had my ups and downs," he told the club's official website. "It wasn't nice - you want to be playing every week.
"But then again, the most important thing is the team and that is what the team needed.
"I worked on my fitness and sharpness and came in much earlier every day to work in the gym with the fitness coaches and the physios. There was a lot of stuff to be done - I realised I wasn’t in the best shape, but it all worked out pretty well.
"Hopefully I can be the club’s number one this season. It is important, I want to win a trophy for this club because that is what is missing in my career and I’m sure it is what the fans have been missing. It’s a big season."
The Pole has renewed competition for his place this term after Wenger added Emiliano Viviano to his goalkeeping options before the transfer window closed.
