Sonny Bill Williams says his triumphant climb to the top of two rugby codes was only possible because he walked out on Canterbury.

Williams has repeatedly apologised for the controversial manner in which he walked out on the Bulldogs in 2008, and he’s at pains to emphasise he’s not pointing fingers at his former NRL club.

But the dual premiership winner and dual international says he failed to handle a negative football culture at Canterbury and urgently needed to come to terms with the man in the mirror.

Williams let the partying life get the better of him and admits he’s “embarrassed” looking back at elements of his past.

The 28-year-old was instrumental in the Roosters’ 26-18 grand final win over Manly on Sunday and is currently the most sought-after athlete across league and rugby.

But opening up post-match, Williams said his rise into superstardom has only been possible because of his decision to return to the values that originally moulded him as a footballing prodigy.

“When I was a youngster I fell off. I never touched alcohol until I made first grade,” he said.

“Growing up I was really dedicated to my craft and just wanted to be best I could be.

“I lost my way for a couple of years there but I’m proud to say I’m proud of the man I see in the mirror.”

Williams, now a devout Muslim, said the culture at the Bulldogs didn’t allow him to be the best man he could be.

However, he refuses to pass the buck.

“I’ve got to take accountability for my actions,” he said.

“I guess looking back I went through embarrassing times.

“But I feel confident as a man, as a person that I represent my family as I was brought up to.

“That’s my mindset these days and I’m just happy.

“I’ve had good men around me and good environments and love of family.”

As an 18-year-old, Williams won a premiership in his first year of NRL.

He fled to rugby, a maligned figure. But in time he had a World Cup win as an All Black and a Super Rugby title with the Chiefs.

Now, in his first year back in the code he walked out on, he’s once again powered his way to the summit.

But as he prepares to make the next big decision of his career, crucially he also has the respect to go with the silverware.

In 2004, it was a question of how good?

Come 2013, Williams is a player who can safely say he’s fulfilled his enormous potential.

That’s no mean feat, especially given he still has a quarter of his career ahead of him.