(You may be relieved - as I was - to learn that times have changed at WHS. A "positive behaviour for learning" approach is used now, and boys can choose to wear their hair long if they please, as long as they tie it back.)
After school, Jack went into hospitality, going from dishwasher to sous chef to barista. It's easy to imagine Jack entirely at home in Wellington. So what brought him back to Whanganui?
Stinkfest: a three-day music festival associated with a very underground music venue called Stink Magnetic.
"It was crazy, esoteric music and I fell in love with the whole ethos," Jack recalls.
"And the freedom here ... there are wonderful people and everything's easier and cheaper in a small town."
And so, back Jack came. For a while he ran the little cafe in the UCOL atrium, and the cafe at Windermere Gardens. But Space Monster is what made him a bit famous - and not just in Whanganui.
It was part of the buzzing, creative, entrepreneurial scene that is changing the face and image of Whanganui.
Space Monster was a music venue in Drews Ave that developed a cult following around New Zealand. It was eventually shut down in November 2015 because of building compliance issues that couldn't be resolved with Whanganui District Council.
But for the four years it lasted, it offered locals a new kind of place to gather and to get involved.
And it was never as underground as some people thought. You didn't have to know someone to find it - I mean, it even had its own Facebook page. And it attracted a wide range of people of all ages and backgrounds.
About a year ago, Jack's new venture arose - a collective creation with Nicola Van Weersel and Katherine Claypole: Article.
Article spans genres: Is it a cafe? A gallery? A vintage shop?
It's all of those things and most of all feels like Jack's living room, where people gather sociably around large tables.
Article is open only on the weekend - "I don't want to make coffee all week," Jack says. "I do lots of little things to avoid having to work fulltime at anything."
For sure, that is one of the freedoms possible in a small town with cheap housing.
What else does he like about Whanganui? No traffic, living by the river.
"Jobs are really important but it's not the only thing. People need a social community they relate to. People need to make money but they also need to have fun."
Jack reels off names of young people who have moved here recently from bigger cities.
First they need a reason to visit. Then, "You've just got to show people a good time." Jack grins - "a good time" likely involves hanging out at Article, some live music at Lucky Bar and grabbing a burger at The Citadel.
The owners of this trio of new venues are all mates. Their personal friendships have become a supportive business network. There's no sense of competition, says Jack - "We all help each other out."
Jack - whose latest venture is Loud'n'Clear, which hires out sound gear for parties and events - was recruited on to the council's consultative group considering the Town Centre Regeneration Strategy.
Its chair, councillor Helen Craig, says Jack was approached because he was a younger voice, an entrepreneur, and, because his father Ross owns a lot of heritage properties, Jack has some experience of what it's like to own a building in town.
His friend Jamie Waugh is now also involved, council being impressed with his role at Progress Castlecliff.
Jack's very optimistic about Whanganui's future. "There are so many amazing people doing amazing things.
"And I like that the rest of New Zealand doesn't think we're that cool. There are no cool kids here - there are fewer cliques, less social stigma bullshit."
You'd have to say, Jack is the real kind of cool. Zero posturing, just genuine, friendly, smart - and out there making things happen.
-Rachel Rose is a writer, gardener, fermenter and fomenter - more on this story at www.facebook.com/rachelrose.writer
