No excuses for 'bad boy' Guildford
His career has been blighted by drink problems, which he traces back to his father's tragic death.
The 26-year-old is raring to go again after joining Australia's 2014 Super Rugby champions on a 10-month contract in September.
The wing is confident enough now to be giving media interviews in Sydney ahead of the new season starting in February.
"Can't say I'll never, ever drink again, but for the moment I'm pretty happy not doing it," Guildford told The Australian newspaper.
Personal tragedy struck in 2009 when his father Robert died of a heart attack watching from the stands as Guildford and his New Zealand team-mates won the Junior World Cup in Tokyo.
"It messed me up big time," Guildford told foxsports.com.au.
"I went from I guess jubilation and then five minutes later I found out that my dad passed away, and I'm looking in the stands and my mum's crying."
It set off a descent from World Cup heroics to serious alcohol problems and his sacking from the Crusaders in 2014.
"I used dad's passing as an excuse for a long time. But I can't keep using it as an excuse until I'm 40," he said.
"I need to make my dad proud and play some awesome rugby and do well off the field."
Guildford first went to France, but walked out of a contract with Top 14 side Clermont in May, citing "personal reasons".
It was Waratahs head coach Daryl Gibson – his coach at the Crusaders – who talked Guildford into a move to Australia to embark on a fresh start.
"It showed me that he wanted me as a rugby player and to be a part of an organisation, but also that he actually cared about me outside of rugby," Guildford said.
After the signing, Gibson acknowledged the wing faces a challenge to fit in after the tumultuous years.
"He's probably been carrying that 'bad-boy' baggage around with him for the past few years, and from my observations he has moved past it and grown up a bit," Gibson said.
Guildford played 11 Tests, debuting against Wales in 2009, and was a part of New Zealand's 2011 World Cup-winning squad.
Alcohol problems first emerged publicly during the tournament and just weeks later he had a meltdown in the Cook Islands, running naked into a bar and punching two men.
Then in January 2013 he allegedly became involved in a brawl at a party in Christchurch, prompting him temporarily to withdraw from rugby and seek help.
Now he says he is working to get his life back. The Waratahs kick off their season on February 27 against the Queensland Reds.
"I want to beat those Kiwi teams more than anyone," he told The Australian. "I can't wait. I'd play tomorrow if I could."
Agence France-Presse
