He now lives and works just 50 seconds away from the Norsewood Fire Station where he has been a volunteer firefighter for 33 years and fire chief for seven.
Ahern's amazing work record, includes just two sick days in those 40 years.
"Norsewood has been my life, but if I didn't enjoy it, I wouldn't still be here," he said. "It's a good life, because at the end of the day I can still knock off and go and have a beer. It's just a good place to work, but, sadly, a lot of the people I worked with have passed away, the young and the old. We all started here as kids."
Working at was then Norsewear Industries Ltd, a company started by Ola Rian, an ex-Norwegian soldier and ski jump champion, who emigrated to New Zealand in 1967, Ahern took on a textiles course at a polytechnic in Auckland between 1981 and 1983. But he always returned to the Norsewood factory to work in the holidays.
"This has always been an interesting place to work and through all the ups and downs I just carry on," he said.
When he first started work, it was on the knitting machines and it was shift work, with the factory closed for just 24 hours each week, from 10pm on Saturday until 10pm on Sunday.
"At the height of the business there were 100 people working here and Norsewear, as it was then, made a foray to Takapau where I worked in the sock plant," he said. "The company also had a branch in Tasmania, but I didn't go there."
The factory is central to the Ahern family. Terence's wife of 30 years, Lisa, works there and his three children also had stints too, but for one son, Mathew, it was just a holiday job. He's now a teacher at Lindisfarne College in Hawke's Bay. Ahern's other two children now live in Australia.
Ahern, known as Tingy to his friends, doesn't think any of his five grandchildren will work at the factory.
"The support this place has given to our community has been unbelievable," he said. "With three or four volunteer firefighters working here, there's never been any hesitation in letting us race off when the siren goes up. There are times when I have to pop up to the station and could be away for an hour. That's the community spirit of the Kiwi Sock Company and anything the company can do to help the brigade, they do it.
And although Ahern now has the job title, technician, he said in such a small work environment, it's about doing "everything".
"If there's a job to be done, you do it. That's how we survive," he said.
There are 24 full-time staff at the factory, from Norsewood, Waipukurau and Dannevirke, significantly less than the 80 staff when Norsewear was the biggest maker of knitted outdoor garments in New Zealand.
"It was a bit of a sad day when the garments went because I'd spent a lot of my time working on jerseys," Ahern said. "Although a lot of people were made redundant, they all received a lot of support and found jobs.
"Then nine or 10 years ago when we were going down, Scanpower, Manawatu Knitting Mills and Wayne Russell purchased the business."
The Kiwi Sock Company now manufactures socks, hats, gloves and scarves under the famous Norsewear brand. And yes, Ahern always wears the company's socks, as do his family.
"The first thing the kids ask for when they come home is the socks," he said.
While he lives just a few seconds from work, Ahern has travelled overseas for work, but he's always pleased to get home again.
"I've been to Germany and Italy twice over the years to learn about new technology, look at their factories and undertake some training courses," he said. "One of the new things coming is digital printing machines which will open up a whole new avenue of things."
Through the decades Ahern has worked with some characters - Wayne Russell and the late Steven Hyde have had a big influence on him.
"They have been two good guys to work with. With Wayne still here, we've worked together for close to 40 years," he said.
Ask Ahern if he'll still be at the factory when he retires, he said it's hard to look into the future.
