The Brazilian international made his Arsenal debut in the Gunner’s 2-1 Premier League home victory over Burnley after his move on the EPL transfer deadline day.
Chelsea, who defeated Arsenal in the UEFA Europa League final, came 3rd in the English Premier League last season with Arsenal coming fifth.
“I am a guy with ambition and that is why I moved. I like a new a challenge and new things in my life,” said Luiz.
“This is what gives me oxygen and gives me motivation and also to really enjoy this moment.
“I could have chosen a comfortable zone and got money and be cool and that is it.”
However, the new Chelsea coach, Frank Lampard has told David Luiz he will not be a guaranteed starter in his team and then allowed the 32-year-old defender, who won 6 major honours in two spells at Stamford Bridge, to secure a move across London to the Emirates Stadium.
David Luiz is expected to play a big part in Unai Emery’s plans. He played alongside Sokratis as Arsenal gained their 2nd win from 2 Premier League games this season.
“Everyone knows I was so happy at Chelsea and won many trophies there,” added Luiz. “I had a real honest conversation with Lamps, and Lamps had different ideas for his plans for the year.
“So the best way for me to respect the club where I can was to move on, try a new challenge and give him the opportunity to do his job.
“My philosophy on life is to be positive and to be a dreamer. I have my health, I can dream and we [Arsenal] can fight for something big.”