The Slovakia international admits he could well have been playing for the Rossoneri had it not been for the intervention of Walter Mazzarri and Aurelio De Laurentiis
At the time of the proposed deal, the Rossoneri had just claimed the Scudetto after pipping the Partenopei in the title race and were keen to bring the Slovakia international to San Siro - only for two high-profile figures to intervene.
"[Aurelio] De Laurentiis and [Walter] Mazzarri told me I was wrong to want to leave," Hamsik told Guerin Sportivo.
"We had just lost the Scudetto after being defeated by Torino, Sampdoria and Bologna.
"I spoke with the president and then with Mazzarri and both explained to me why they did not want to sell me. According to them, I would be making a mistake to accept Milan's offer. It was valuable advice as I am happy now in Napoli. I have just bought a house and people love me here for who I am."
Though they have not won the league title since 1990, Napoli have enjoyed one of their better periods in recent years and the 25-year-old puts much of their success down to Mazzarri.
"Mazzarri is the secret weapon. If we have achieved extraordinary results these past years, it is mainly down to him," he continued.
"I do not think he will leave."
Hamsik has once again played a key role in another successful campaign for the Naples club, scoring 10 goals and setting up another 19 in all competitions.