Mertens has played a key role in Maurizio Sarri's men establishing a one-point lead over six-time defending champions Juventus in the race for the Scudetto and, having rebuffed interest from China last year and been linked with Premier League heavyweights Arsenal and Manchester United, the Belgium forward is loving life in Campagnia.
He told Il Mattino: "I'm playing and having fun on the pitch and I’m very happy. I'm happier now than I've ever been before.
"I feel like a kid in a toy store at Napoli and I feel like I can see all of my wishes come true."
On a potentially lucrative switch elsewhere, particularly to China, he added: "It happened last year, this year nobody called me.
"The temptation was there, it's normal and human, but I wanted to stay here. And I still want to stay here."
Napoli visit rock-bottom Benevento on Sunday with Mertens willing to play anywhere to help Napoli break Juve's domestic stranglehold.
"To win the Scudetto I'd play full-back and goalkeeper if Sarri asked me to, even if [Pepe] Reina wouldn't be too happy!"