De Bruyne scored on his debut in victory at Sassuolo on the weekend.
Speaking to Corriere della Sera about his decision to move to Italy, the veteran midfielder said: "Napoli, the only real offer? No, the best option. There were many offers, but I chose the Italian champions, they are playing in the Champions League, and (Antonio) Conte is a magnificent coach.
"When you're young, you only make decisions for yourself. Now I've also asked my children, the eldest is 10 and is in an important phase of development."
The Belgian continued: "When (Manchester) City decided not to renew my contract, I started looking around. After such a long time, I no longer wanted to stay in England. Among the various options, Napoli seemed the best for my family and for me as a footballer. I can still play at a high level in Serie A."
And to those who call him old , the 34 year-old responded: "I think I'm more or less the same as I was 10 years ago. Maybe when you're younger you're more dynamic, now I have more experience. You're evolving as a player: I have my qualities, people know them, but also my weaknesses, like everyone else. I'm not worried or excited: I just try to do my job to the best of my ability, having fun.
"Football is my passion, and I don't want it to become just another job. If you enjoy it and put a smile on your face, you end up playing better."