Slater earned a recall to the Kangaroos squad this week after his stunning return from two shoulder reconstructions which sidelined him for 18 months.
He starred in Melbourne's NRL grand final triumph over North Queensland on Sunday, claiming the Clive Churchill medal.
"I've played one game for Australia since winning the World Cup so to get back to where I am and be selected in that squad is great," said Slater at the Storm's end-of-season awards night after announcing he would play on in 2018.
"I love playing for Australia; you stand there and sing the national anthem and think about all the people that you're representing so it's very exciting."
The 34-year-old will don the No. 1 jersey in Australia's World Cup opener against England on October 27 at the Storm's home ground, AAMI Park.
Slater's last appearance for Australia was in the 2014 Anzac test.
"To open the World Cup down here in Melbourne will be great," he said.
"We played a game here in 2008 the week my daughter was born and then we played another one in 2010 which was the first ever game at AAMI Park so it's great to represent your country in the city you live in."
The grand final celebrations for Slater and his six Storm teammates selected in the 24-man Australian squad end on Thursday when they gather in Sydney before departing for an exhibition match against Papua New Guinea and Fiji on October 14.
Slater surprised his Melbourne teammates at the awards night with news he had signed a new deal for 2018.
He said he made the final call following the grand final with the firm belief his body was up to it.
"I've never doubted myself; the only doubt I had was whether my shoulder would allow me to play again," Slater said.
"My performances this year haven't surprised me because I expect myself to play good and when those performances drop below my expectations, I will give it away."
