They come from hardy stock up in Oslo, Norway, on the northernmost end of the Oslofjord.
"There is not," assures University of Denver Pioneers' head knock David Carle, "a wasted day, a wasted hour, a wasted moment, in Emilio Pettersen's body.
"This is a super-super-competitive kid.
"He's a huge piece of our program and our pursuit of another national championship. We think we have a real good chance at it this coming year and the years he's with us.
"We were real excited about his growth as a player and to watch him build off the foundation he's put in place.
"There's no reason he can't be even more impactful in the years to come."
Attending his second Flames development camp out at WinSport, the Manglerud, Norway-born Mathias Emilio Pettersen (a reminder: at home in Norway, he goes by Mathias. In the North America, he answers to Emilio) is one of those prospects whose name alone makes team scouts go all dreamy-eyed or unconsciously puff out their chests.
"Having been to one of these before you know what to expect,'' says Pettersen. "But you also know you've got to be better than last year.
"Meaning you've got to be better in testing, on the ice. That's what they're looking for. And if that's what they're looking for, then that's what you're looking for."
The 5-10, 170-lb. left-winger's initial year on the Colorado campus could only be described as a whopping success, second on the Pioneers in scoring as an 18-year-old, accumulating 30 points in 40 outings.
"Most of it," Pettersen deflects, "is who I was surrounded by all year. Coach, everyone, really helped me to adjust quicker and also be able to adapt to our systems.
"It's always, wherever you are, whatever level you're at, the quality of people around you and how you treat them that matters. I took care of that first, showed everyone that I'm committed first and foremost to the team and its success, and that helped me fit in more easily."
Both player and coach arrived at Magness Arena on the U of Denver campus together, Carle taking over after Jim Montgomery exited to take the Dallas Stars' job.
"Emilio enjoyed a really good final junior year up there in Muskegon (USHL), arrived here with a lot of confidence and played a pretty prominent role for us from Day One,'' lauds the boss.
"His offensive ability is what obviously stands out for people but he became a much more responsible defensive player, without the puck and with the puck, managing the puck, picking his spots; when to try and do things and when to live to fight another day. Whether that be at the end of shifts or up a goal, etc.
"His game just matured a lot throughout the year. Very receptive, very open to coaching, to learning. Super coachable.
"What was also very apparent is the way he cared about the team's success over individual success. That allowed him to grow a lot within himself but also within our team structure."
Video: "Motivation - that's what it brings"
The Pioneers are one of the U.S. college game's historic powerhouses, having been a part of 17 Frozen Four Tournaments and are seven times NCAA champions.
"We take our hockey very seriously here and the development of players very seriously,'' says Carle. "Emilio is a reflection of that."
Any words of encouragement/advice for the teenager en route to what he aims to be his future professional home in Calgary?
"You don't need to give Emilio too many pointers," is the amused reply. "I think last year, at his first camp up there, he won the coaches award as the most coachable and improved guy thought the week.
"So Emilio, he doesn't need a lot of advice-giving that way.
"He's real excited for another chance to showcase himself. He's a proud draft pick of the Calgary Flames. He'll put his best foot forward at camp, that's for sure."
For Pettersen, these next four days are to be used to the fullest.
"I have no timetable in my mind. Next year, I want to push my limits, to be better. That's all."
No different than his coach, though, an NCAA title is very much on his mind, in his imagination.
"A hundred percent. I hundred percent. I thought we could've done it last year. With the team we had, nobody really expected that.
"We're going to prove people wrong again. No matter how many players we lose over a summer, we'll always, every year, be in it to win it."