"My job then really was a whole load of bull." This is a man whose humorous veins run deep.
With his sights set on a PhD and bolstered by a scholarship, the newly-capped Kiwi joker joined Colorado State University, a savage culture shock.
"The university was three times the size of Kawerau, in today's terms it would be real Trump country, very very conservative. Football and country music were the main interests. I can only tolerate an hour of country music and couldn't stand football."
Being perpetually broke compounded his woes. "The scholarship was paid in Kiwi dollars, the exchange rate was horrific."
But there were upsides. One, Professor Temple Grandin, "the most famous autistic person in the world" after becoming adviser to Dustin Hoffman on his Rain Man movie, became a close friend.
The second longest-held Islamic hostage, the late Tom Sutherland was another. "I was his dog sitter, spent many nights drinking whisky with him, hearing his stories."
Regardless, Paul's despondency grew into full-blown depression.
He returned home briefly then it was back to the States working in dog genetics, based near Sacramento.
Enter running. "Everyone there ran, I'd never done any, I'd go walking in the Sierra Nevadas and all these runners would pass me training for the Western States 100 mile [160km] endurance race."
Paul progressively upped his pace, joining them. "The depression just went away."
But his first race wasn't to be, out-of-control wild fires forced its cancellation; his second was a disaster; 24km from the finish line he tore a hamstring ligament. "I was pretty damn gutted."
In February 2008 he quit his job "the company was going bust", heading to Mexico. In the Copper Canyon he met and mingled with the indigenous "super human" Tarahumara people, famous for their barefoot running; enigmatic American ultra runner, the late Caballo Blanco, who lived with them, became his mentor.
"His knowledge about New Zealand was limited to kiwifruit, he named me El Kiwi Salvage after them, it translated into 'savage kiwi', I guess something was lost in translation."
Paul mourns the ruination of the Tarahumara's way of life by all-powerful drug cartels. "They came in built roads, introduced cars, the locals no longer ran."
But that was to follow his time in the place where the Tarawera Ultra had its conception.
"The rugged country fascinated me, I knew we could match it in a different way, that our environment would be ideal for something similar, that people would come across the world to run our ancient trails, experience our culture, history."
The start gun was fired for the first Tarawera Ultra in March 2009, the field tallied 62.
It wasn't intended to be a money spinner. Paul took odd jobs, picking blueberries and web designing.
"My mother was saying 'why don't you get a real job, like being a policeman, you can't make a living out of people running in the bush', she was right."
Paul became a science communicator with Scion.
"I was translating science into plain English." There'll be many non-boffins glad to hear that.
Four years on the Tarawera Ultra's growth demanded his attention full time.
His initial pipe dream of it being an international draw card had become reality.
"It got way, way way too busy to be a hobby, growing astronomically."
Two years ago Paul recruited conservationist Tim Day "the guy who invited pest-proof fences" as his business partner.
Tim's first ultra was a cyclone-force baptism.
"Cyclone Lucy was brewing, predicted to hit two hours after the race started, safety concerns meant we couldn't operate the boats mid course, at the last minute we scrapped them for an extra forest run loop. Tim finished marking the new course at 4am, we had a shot of whisky and were back on the job by 6am."
Seventy per cent of the hardy entrants finished the reconfigured course. "They are a tough breed, ultra runners," this master of understatement says.
A 160km endurance race was introduced this year.
The pair had already added the Waitomo Trail Run to their repertoire, billing is the "overland, underground trial adventure". Todayit celebrates its third year with 3000-plus runners and walkers tackling differing course lengths, longer courses incorporate caves.
Why Waitomo? "Tim and I looked at Google Earth, thought its landscape was pretty amazing, it's one of the most unique geological areas in the world."
There's now a third member of NZ Trail Runs company, German-born Sarah Rosenbaum. She and Paul have become partners at work and out of it, their meeting sparked by Paul's discovery of a Colorado State University water bottle a volunteer dropped clearing trails.
Paul traced it to Sarah, she too had studied at Colorado, acquiring a masters in tourism management.
Away from the company she specialises in dog photography. The couple have two farm dogs Paul calls"'our working non-working dogs". "Our days are spent entertaining them."
But it's organising ultra marathons and trail running that's become the "real job" his mother pleaded him to take.
"Living in different parts of the world I ruminated on introducing ultra marathons to New Zealand, they've gained the reputation internationally of being the friendliest ultras because of Rotorua, its environment, culture, hospitality."
PAUL CHARTERIS:
Born: Rotorua, 1971
Education: Otakiri Primary, Edgecumbe College, Massey and Colorado State Universities
Family: Mother Anita Charteris, partner Sarah Rosenbaum
Interests: Running. "Our dogs, jumping in creeks with them, exercising them in Scion dog park." Mountain biking, "Working on our house and garden". Web development." "Cooking healthy meals."
On his life: "Extremely fulfilling."
On Rotorua: "The welcoming, friendly place."
Personal philosophy: "You just have to get to the start line."
By the numbers :
First Tarawera Ultra field 2009: 62
2018: 1350
Inaugural 100 mile (160km) endurance race 2018: 130 runners
Inaugural Waitomo field run 2016: 1950
Today: 3000 plus
Oldest entrant in an event: 82
Youngest: 17
Social media followers: More than 40,000
Amount generated for local economy: Significant and compounding
