Benitez won the Italian Super Cup and the Club World Cup with Inter Milan in 2010 in his first spell in Italy, but was sacked after just six months.
Now back in management after a successful spell as interim Chelsea manager last season, in which he guided the Blues to Europa League success, his new club are sitting second in Serie A after collecting 16 points from their opening six games.
Benitez used funds from the big-money sale of striker Edison Cavani to reshape his squad, including bringing in Gonzalo Higuain, Raul Albiol and Jose Callejon from Real Madrid, while Pepe Reina arrived on a season-loan from Liverpool.
He is up for the challenge ahead of trying to guide his new club to their first Serie A title since 1990.
He told the Daily Mail: "I met the president and I liked the challenge. I could feel from the first day the passion and the idea to improve was there.
"We knew that maybe Cavani would go, so we had to be sure about signing the right players.
"I've signed four or five players with this money, all with international experience, who can give the message to the rest of the world that Napoli is growing."
Superstar Diego Maradona was at the club when Napoli last lifted the title and Benitez wants to also bring success.
He added: "Everybody talks about Maradona. Everybody enjoys football here and so he is an idol and it's important for everyone. He was one of the best players in the world and he made the difference.
"I think it's important to have idols in the past and big names here now and what we have to do is think about the future."
Napoli take on Arsenal in the UEFA Champions League on Tuesday and Benitez admits he does not know if his side can win the tournament.
He said: "It is too early to say if we can be contenders.
"There are many strong teams. You cannot question the quality of the English clubs, but you can see the other teams are improving too. You have to keep moving forward."
Meanwhille, Benitez has the full backing of Reina, who believes the Spanish tactician has improved since the pair last worked together at Liverpool.
The keeper said: "He's the best manager I've worked with.
"He's just as good as ever. If anything, he is probably a little more complete, with much more experience. He has become a much better manager."