Even Mr Bethune thinks being back in his own bed every night after 47 years as career firefighter, will be a "bit strange".
But now, at 67, "the time is right" for retirement.
"I've got mixed feelings about it. It's never been hard to go to work. No two days were ever the same."
The senior station officer started as an auxilliary fireman at the former Roslyn fire station in Roslyn Village in 1962.
He will work his last shift at the Roslyn fire station in Nairn St, where he has been posted for the past 10 years, on Friday - 47 years to the day since he started as a professional fireman.
His earliest recollection of an interest in the Fire Service was taking a ride on Milton's new fire truck as a schoolboy.
It was after being involved in the McKenzies store fire as a 20-year-old auxilliary firefighter in 1963 that he thought: "This wouldn't be a bad lark", and decided on firefighting as a full-time job.
A few things had changed in the service during 47 years.
For one, there were fewer fires, thanks to better constructed houses, smoke alarms and fire safety education.
Training, too, was a bit different these days.
"I started as an auxilliary and got told to sink a standpipe and run out a hose.
Half an hour later, I was a firefighter."
Nearly all the technology had changed, from the fire appliances, to the uniforms, to the way people on station were woken up (clanging bells have been replaced by automatic lights-on and a crescendo noise).
But some things there remained the same - young people for one.
"When I started, it was always gorse fires. Now, it's burnt-out cars."
And the people he worked with had always been great.
"The [Fire Service] really is like a big family.
"It's been a lot of fun," he said.
Mr Bethune has also set a record, not that he wants to boast about it.
He is officially the longest-serving career firefighter in the South Island and the third longest-serving career firefighter in New Zealand.
"I didn't go into it thinking about that sort of thing. I used to look at the 60-year-olds when I started and think, 'Boy you're old'."
As for the future, he planned to take a holiday with wife Norma to the United States and finish a scale-model railway in his back yard.
After that, who knows?
But look around at any major fire in the future and you might catch him watching from a distance.
"You can't help it - it's a part of you."
