The Italy international left the Hornets in the summer in a permanent deal. The Pozzo family own both clubs.
He told Gazzetta dello Sport: "At Watford the cycle was over, Pozzo opened my return and luckily I still hadn't sold the house.
"Besiktas? I almost said yes, the contract was advantageous. And Udine is better than London."
On his future, Okaka seemed to have pretty clear ideas: "I would like to become a symbol. Playing in this city and in this club is an honour."