Less than a month ago, Carlin spoke of his excitement about the Commonwealth Games returning to Glasgow next summer. Not least because he is now living near the Sir Chris Hoy Velodrome, where the cycling will be held.
But his decision to quit had already been made and retrospective examination of what he said at the time shows a vagueness about his ambitions for that event.
As a potential poster boy for the reimagined event – as a kid he sat rapt in the tribunes in 2014 and won medals at the next two Games – was it a wrench to walk away from the chance of a glorious career conclusion?
“It’s been the elephant in the room,” Carlin said of Glasgow 2026.
“People I’ve told have asked, ‘what about Glasgow?’ but it’s less than a year away and I’d be doing myself and the jersey a disservice if I decided to try and put it round my back again when I’m just not in the shape to do it.”
Carlin does not need that elusive gold medal or one more wave of adoration from a home crowd to validate his achievements.
They are achievements that place him fourth in the list of all-time Scottish Olympic medal winners, behind only Duncan Scott, Sir Chris Hoy and Katherine Grainger.
As he says, plenty of his competitors will leave the sport without ribbons around their neck and precious metal in their hands.
Like him, they will have memories, experiences and friendships, and it is those – as much as the medals – that the Scot will cherish when he reflects.
“It’s rare that someone steps away when they’re still rubbing shoulders at the top,” he adds. “But you have to be able to give 100%.
“I can come away from this saying ‘I gave everything I could, I gave my whole body to this sport, and I’m satisfied’. I couldn’t do anything more. So I can’t be upset.
“I started this journey when I was 14 years old and my mum and dad gave up time and money that we didn’t have to let me chase that dream.
“And if someone said to ‘Wee Jack from Paisley’ a decade ago that he’d have four Olympic medals around his neck, he wouldn’t have believed them.”
