Smith said there were weekends when he was unable to play for Melbourne where he was lying on the couch at home exhausted physically and mentally — and he believed few realised the toll playing at that level took.
"I couldn't quite back up after any of those Origin matches and maybe that was a sign there that it was time," he said. "Because I have always been very proud of my ability to back up."
Smith paid tribute to several coaches and his family. "The people that have sacrificed the most are my family," he said. "My beautiful wife Barbara and my children. My eldest has been to pretty much every rep game. I've been away from you for a long time but you've always wanted me to pursue my dreams."
After Smith finished his statement, Walters joked about whether it was too late to convince him to play "two 30-minute spells".
"I take my hat off to you mate," Walters said. "I think his performance in game three of last year's Origin performance was one of the best I've seen of anyone at that level and that was at 34 years of age."
CONTENDERS FOR CAPTAIN AND NO. 9
Smith's exit coincides with the representative retirements of Johnathan Thurston and Cooper Cronk, which were announced at the end of last year.
It means Queensland will need a new captain and hooker for the State of Origin series starting on June 6. "It's a massive blow," Walters said.
The call is likely to springboard Brisbane hooker Andrew McCullough into contention for a Queensland debut in game one, while Jake Granville of the Cowboys could be another option.
Darius Boyd, Billy Slater or Greg Inglis are the most likely candidates to take over the captaincy, however Boyd has battled form and fitness at Brisbane this season.
"We'll get to that in the next couple of weeks," Walters said.
Since making his debut for Queensland in 2003, Smith has played a record 42 Origins for the Maroons and has been captain of the side since 2012.
In that period he has missed just one game - the series opener in 2010 due to injury - and won a record 26 matches.
Since playmaker Thurston's debut in 2005, the pair have played a crucial role in the Maroons' 11 of the last 12 series victories.
Bookmaker TAB immediately dropped its price for a NSW series win from $1.70 to $1.53 in the wake of the announcement. Queensland lengthened from $2.15 to $2.50.
Smith's rep exit comes with all three Queensland-based NRL sides languishing in the bottom half of the ladder.
The Broncos (5-5), Cowboys (3-7) and Titans (3-7) have all underperformed this season and Queenslanders were looking for their Origin outfit to lift their spirits.
