John Kirwan tackles his 'generational' bias

All Black great Sir John Kirwan has spent his post-rugby career helping the vulnerable - and it's now challenging what he knows about himself.

The 52-year-old is a mentor at the School of Hard Knocks charity, which puts people with a troubled past on a new pathway.

"It's basically just getting guys who want to turn their life around and what we use is education, rugby, [and] fitness," Kirwan told The AM Show on Thursday.

The self-proclaimed "generational racist" says being a "middle-class white boy" meant he often held pre-conceived ideas on others.

"So I walked in last year for the first season thinking if you work hard and you do this and do that, life will be okay for you.

"But I have to challenge all those thoughts because a lot of these guys have really difficult backgrounds and have really big challenges in their life, and one mistake that often costs them a lot."

One of those guys is Lincoln - a young man who's had trouble with the law in the past, who Kirwan mentors in the programme.

"Being brought up has been up and down… I had some good times and had some hard times," Lincoln said.

"I just wanted to get out of home, so [the programme] keeps me focused and hopefully [I'll] get that certificate at the end."

Kirwan puts confidence in him to achieve that goal - a sentiment that brought the former sports star back to his own youth.

"I thought I was dumb all my life," Kirwan says. "I probably am dumb - because I was told at school that I was dumb so I thought that. But I'm not dumb, I'm just not educated.

"Often I could see the potential… but a lot of the guys on the course don't think they're good enough or [think] I can't do that.

"Lincoln's smile was the first thing I saw, and then the second thing I saw was the bracelet that wasn't on his wrist, but on his ankle. So I was really intrigued straight away.

"They've been great, these guys, they work really hard in  the classroom which is tough, get them in the gym, trying to get the smoking stopping and they blow pretty hard at times… but I'm really proud of them."