So, he gave up his intended career path to becoming a cardiac physiologist, diverting to become an amenity horticulture apprentice instead.
"This is where I belong in this part of my life," the 28-year-old Cantabrian says. "I have a degree in Human Anatomy and Physiology. I worked at Ōtautahi Hospital as a phlebotomist and then a cardiac technician. They were looking to nurture me for the role of cardiac physiologist - but it just didn't fulfil me."
River's parents, he said, were initially unsure of his career change but now applaud the move as they can now see how happy he is.
"At high school, you're guided towards a career because you are good at some subjects and hate others - but all you want to do is hang out with your mates," he admits.
"My parents saw in me a book-smart kind of personality. And they said, 'Let's make him shoot for the stars, let's encourage him to study to perhaps be a doctor one day'.
"After my first year when I didn't get into medicine, I wanted to change, to do an outdoor pursuit but I was convinced to continue. It was a big move for me to realise that all this time and money that I'd spent studying health sciences was not actually where I where my future lies."
River went traveling for a much-needed study break - including a stint chalet hosting in the French Alps, as it would allow him to indulge in his passion of skiing and snowboarding. The trip was extended due to covid, and when he came home 18 months later, River was looking for roles that would allow him to continue to be outdoors.
A taster of various Primary ITO apprenticeships including a six-week placement at the Botanic Gardens in Christchurch, piqued his interest. He moved to Pōneke Wellington and took on an apprenticeship at Wellington City Council. It was expected to be three years, but this high-achieving student finished it in two.
"Then I was looking for something to do. I really like just switching things up, and saw the Young Amenity Horticulturist comp come up," River explains. "I wanted to use the competition as an excuse to improve myself professionally, but perhaps personally as well."
He won the Young Amenity Horticulturist of the Year and will now compete in the prestigious Young Horticulturist of the Year, a competition involving six horticultural sectors, in Auckland next month.
He hopes all those years perfecting studying techniques will pay off.
"You put in a lot of mahi when you're at university, it's ways of learning that I've spent years working really hard at perfecting for me."
On reflection River is happy he decided on the career change.
"Being outside, solving problems with my hands, learning about botany is fascinating. There's a lot of bleed over from human physiology and anatomy into cell biology. This apprenticeship has changed how I see the world."
When he is not working, River is often still studying - he is learning Japanese and French - and if he cannot be outdoors taking part in hiking and ocean swims, he enjoys foreign cinema and cooking.
It would be hard to believe, but this active relaxer also finds time for chilling at the beach.
