"But now I'm confident in who I am. I'm still making bad decisions and I stuff up now and then, but I know who I am."
The 30-year-old, whose father is Samoan and mother European Kiwi, was speaking at the Growing Pasifika Solution conference in Manukau.
The conference, organised by Pacific organisation Le Va, looked at issues such as mental health, suicide and addictions among Pasifika youth.
Williams was one of a panel of high-profile sports people - including former league and rugby stars Nigel Vagana, Jerome Ropati and Pita Alatini - who discussed how to look after the mental wellbeing of high-performance Pasifika sportspeople.
The multi-code star touched on his own experiences with fame, media scrutiny and the pressures of performing.
"I think when I was a lot younger, I was always fighting against being a professional sportsman. I always wanted to see myself as a regular guy.
"But I guess with age and maturity ... once I understood that I was happy and content with myself as a person, I started becoming confident.
"When we all understand, especially the young generation, that it's okay to be you and you're all right to go on your own journey, that helps."
I used to follow people I probably shouldn't have followed ... But now I'm confident in who I am.
He said when it came to the media, he often looked at ways to simplify things in his life - and not read or watch what was said about him.
"From a sporting perspective, I just worry about what my coach thinks and what my peers think.
"If I have their respect, then I know I'm doing well. I try not to read too much in the media because they're either gonna put you on a pedestal too high or underplay you."
Williams later met a group of young people who helped to organise the conference this week. He shared his struggles with identity and the issues he faced because of his cultural make-up; being half Samoan and half European-Kiwi.
"I got into a lot of fights, I guess [because] full Samoans thought I couldn't understand a bit of the lingo - and me just trying to hold my own and then feeling like I needed to prove myself.
"It's hard because I've only come to the realisation that I'm confident in myself in the last four or five years. I wish I could wind the clock back 10 years."
Le Va chief executive Dr Monique Faleafa said such conferences cast a light on issues often seen as tapu (taboo) topics within Pacific cultures.