"Everyday life became who I was going to hang out with. Day in, day out, my friends disappeared and the gangs took over, really. Which did my liver no good at all."
Or his nerves. In another violent moment, he was beaten to the ground and threatened. "I won't lie to you, there were times when I was extremely worried.
"One instance a guy who'd given me a hiding was hovering over me with a bar stool threatening to crack my skull open ... I have to say at times like that one does wonder if you've chosen the right path."
But it didn't entirely surprise him.
"I mean, it's a subculture that largely prides itself on physical strength so there's a constant threat of violence and there were times when things didn't quite go to script and I got knocked over a couple of times ..."
He couldn't complain too much about that.
"It's a kind of occupational hazard. You cannot expect to enter the field for the length of time or that deep in the field and have no problems."
What led to those moments? "Often it's the same as all conflicts come about. A lot of conflicts [are caused by] too much booze and probably I was doing too much talking when I should have been listening."
For the most part, though, he was treated well and doesn't like to talk much about his experience "in the field" - he considers the book is about the gangs, not him. He also worries some of the stories might open him to criticism of how he gained the data, instead of a focus on the data gained.
"A lot of time in the field was incredibly mundane and boring. The lives of gang members are like most people, fairly monotonous and unremarkable."
Mr Gilbert embarked on the research when he heard a lecturer say there was a dearth of material on gangs, about the same time a lot of gang legislation was going through Parliament.
"I think it's important for us, and it's important for policy-makers, because our attempts at countering issues surrounding gangs have been demonstrably poor."
His view is that we shouldn't "wring our hands and say we haven't got it right" and he believesa better understanding of gang issues could help in other areas.
"I think they're like a Petri dish of all sorts of social problems. So if you understand the gangs, you can understand wider social issues that feed into them and that intrigued me."
Part of the problem is the gangs are "poorly understood", something that has come about through the lack of research but also because gang members rarely speak publicly.
"So you often get a skewed side of the story and, more than that, you really only hear of them when they commit what are often heinous crimes, but it's a very small minority we're talking about."
He was surprised when he began. "When I went into this research - and remember, it took a very long time - I had all of the misconceptions and preconceived notions the general public have, so for me this was a hell of a journey because it fundamentally changed how I viewed the gangs."
He said: "Look, I'll speak a bit flippantly. I was somewhat surprised they weren't all rapists and murderers and had horns growing out of their heads. I genuinely thought these guys were going to be something akin to monsters.
"Don't get me wrong - certain groups pick up those members of society who are pretty damaged and there are sort of almost psychopathic members. But for the most part, the most part, they're normal working-class, or under-class, guys with all the same life issues and issues as anyone else. They just happen to wear a patch on their back."
Mr Gilbert told the Herald there was nothing more disarming than meeting a bloke who looked "hard as nails" only to see a much softer side to him as he played with his children.
"And he and his wife are complaining about the bills, and he's got job stress and you realise these guys - for the most part - are no different from you and I."
He comments frequently on gang issues in the media and knows some of his statements can be confrontational.
"Some of it sounds stark because people don't see gang members that way, and I do feel some things I say sound almost ridiculous because they push against the grain. Hopefully the book can change that. I'm not saying gangs are good or not criminal or anything like that at all - I'm just saying there's a bit more to them."
There were some common traits in the gang members he observed. "They don't come from Remuera or wealthy North Shore areas. They form in communities steeped in numerous social and economic issues. They generally have come from very hard upbringings where they've been belted around by their folks, perhaps been wards of the state, their education levels are low and what they're looking for is surrogate family.
"They want what we all want and need, which is a sense of belonging and a sense of status - and the gang provides that."
Mr Gilbert knows it can be a hard sell convincing the public, but asks that they keep an open mind.
"The one thing you can't do enough in an interview, or perhaps at a dinner table conversation or even an hour-long lecture at university, is give people all the information they need to overcome the views they have, and this is why the book gives me that opportunity. I can sort of take them through the journey I went on and, hopefully, people will come out the other side and be much better informed."
He also understood some would still not be interested, or comfortable, hearing the other side. "They might see it as sympathetic but it is demonstrably true. If we want to wring our hands and ignore them, well we can, but we're turning an eye away from the truth and we should never do that."
Gaining the trust of his subjects was tricky. They were naturally suspicious of outsiders so Mr Gilbert had to work hard to gain their confidence so they knew he wouldn't betray them. It wasn't, he says, a case of walking up and knocking on the door and asking for a chat.
"No, definitely not. I hung out in the right sort of bars and met the right sort of people and slowly ingratiated myself, and took it slowly. If they said no, they weren't going to change their mind in a hurry."
Once people realised he was in it for the long haul, he gained their respect. And they opened up their doors, and their stories.
Many of the older ones, in particular, realised their history had been lost and "they'd lived and died for that history".
"I think they want to see that preserved."
His PhD took about eight years, four to five years spent "in the scene".
No surprisingly, his family were concerned.
"I think it's safe to say my poor mother was in a constant state of terror that she was going to wake up and read I was dead [and] buried in a small grave somewhere and, yeah, I don't think it was easy for them but mostly because perhaps they didn't understand it."
Although he believes he's seen a side of gang life that could shatter preconceptions, he remains open to others' views.
"I genuinely believe people will be surprised by the book. That's not to say I have everything right. I'll happily amend my conclusions in the face of superior argument."
Patched: The History of Gangs in New Zealand is published by Auckland University Press.
Looking to the future
Gangs have evolved through the decades and Jarrod Gilbert doesn't think they're finished yet.
"In the 2000s the Mongrel Mob are almost un-recognisable to the Mongrel Mob of the 1970s. Most gangs ... whether they rode bikes or hang on the streets, started as unrestrained youth and now you see grandfathers in gangs, a man in his 60s doesn't act the same as a man in his 20s so we have seen a great change in gang behaviour."
That evolution would continue.
"In recent times they seem to have had a resurgence. Largely through the economics but also maybe because of popular culture, fashion and trends change and gangs are no different in that respect."
He said profit-driven crime existed in the 1990s but it could be very disorganised - now however, it still goes on but Mr Gilbert said it came down mainly to individuals.
He believed the future of the gang scene in New Zealand is linked to LA-style street gangs, who had a very different attitude and outlook.
"Whether or not they will see longevity and [become] established like the patched gangs or merge with existing gangs - either way they have to take a new creed with them which is potentially concerning."
Patched gangs in the 1960s and 1970s were based on hippie ideals to drop out of society whereas new gangs are built on MTV culture preoccupied with hip hop, rap and bling.
"They want the fast cars they want the jewellery and if they desire those things and don't think society can offer legitimate ways of getting them that they will find illegitimate ways of getting them - hence why I think [we will] have problems in the future."
This story was first published in 2013.
