Imagine a stranger — say, two strangers armed with video cameras — approach you one evening in Zilker Park while you’re hanging out with friends, basking in a post-race endorphin glow. They offer you a free trip across the world to spend 72 hours in Stockholm, Sweden.


The only catch? You have to leave tomorrow. What would you say?


For 28-year-old Austin resident Alex Leonard, the answer was easy.


"I’d go to Stockholm. Wait, why would anyone not do it?"


That answer and all the adventures that came after are captured in a viral YouTube video, titled "2 Strangers Swap Lives Across the World for 72hrs!!" It has been viewed more than 1.6 million times since it was uploaded in September. Those two strangers in Zilker Park were Matt Dajer and Ammar Kandil, co-founders of Yes Theory, a YouTube channel with more than 4.4 million subscribers that encourages people to break out of their day-to-day routines and "seek discomfort," the team’s official tagline.


A lot of Yes Theory’s videos are travel challenges with titles like "I Took My Pizza Delivery Guy Around the World" and "I Spent 24 Hours in Korea with No Money." Their most high-profile escapades include persuading Will Smith to bungee jump out of a helicopter and pranking the internet with a fake photo of Justin Beiber eating a burrito the wrong way.


As you might have guessed by now, Leonard wasn’t just getting a free trip to Sweden. He was swapping lives with a stranger he’d never met — one who would hanging out with his friends for the rest of the weekend in Austin.


Like most YouTube creators, Dajer, Kandil and their third partner, Thomas Brag, live in Los Angeles. Brag, who was born in France to Swedish parents, thought it would be fun to show a stranger around his ancestors’ homeland. The group chose Austin for the video’s sister city mostly because they weren’t familiar with the Texas capital.


"We wanted a city where we could really take someone into the ‘real America,’ not the one that many tourists see on the coasts," Brag said in an email to the American-Statesman. "So it was both an opportunity for us to learn about a new part of the country we live in, while also bringing a Swede to a place very foreign to him or her."


The main goal of the project — like many of Yes Theory’s filmed escapades — was to quash stereotypes about different cultures.


"By being able to experience a totally different culture from our own, we come back to where we came from with a newfound perspective of the world, an open heart and mind and a whole bunch of new friends," Brag said.


Brag warns at the very beginning of the video (and later reiterated by email) that he sees Swedes as culturally introverted. He assumed he’d have trouble finding a volunteer in Stockholm to take on their challenge. Yet the very first person he approached, 28-year-old motivational speaker and "professional dreamer" Staffan Taylor, said yes immediately.


Meanwhile, it took Dajer and Kandil almost eight hours in Austin to find a willing participant, though they had assumed they’d find a stereotypically outgoing American volunteer.


Right away, Leonard and Taylor stepped into each other’s shoes.


For Leonard, that meant heading straight from a 17-hour travel day to his new quarters at K9, a glitzy co-living and co-working space that was the subject of a New York Times profile this year, where he was expected to deliver a speech to his housemates. About 50 residents live in the downtown Stockholm building, which features communal lounge and work space, as well as tiny dorm rooms with pod-like beds. Every Sunday, the community gathers, and anyone can take the microphone to speak on a subject of their choice. Taylor, a public speaker by trade, had signed up, and so Leonard filled his spot.


"I’ve spoken in front of maybe 20 people or so, and it’s usually a disaster," Leonard said. "I just don’t deal well with that. But for some reason, as soon as we got onstage, everyone was so receptive to us being there that it made me feel super, super welcomed, super comfortable."


With limited time for preparation, Leonard told the audience about his career as a physical therapist in Austin, his preparation for a 24-hour rock climbing competition and why he said "yes" to this spur-of-the-moment adventure.


"I think the reason why maybe I said ‘yes,’ is because I’m very international as it is," he said. "I’m half French, half Venezuelan, as well. I’ve lived in both countries before moving to Texas, so right away people got excited about that because we had South Americans in the room and we had French people in the room."


After the speech, Leonard mingled with his new housemates, then went to what Brag described to him as the ultimate Swedish tradition: a so-called "crayfish party."


"They eat crawfish and sing songs and drink a lot of schnapps," Leonard said. "They’re all super excited to show me crawfish and teach me how to crack the crawfish, because they didn’t know anyone else really ate crawfish (outside of Sweden). I felt terribly guilty because I’m allergic to shellfish, I couldn’t eat any of it."


Leonard is vegan but gave himself a pass for the trip so he could enjoy his hosts’ delicacies: Swedish meatballs, a potato dish with steak, a quiche-like cheese dish. And the drink of choice, "schnapps" (sometimes spelled "snaps" or "schapps"), isn’t quite the same as what Americans might know by that name.


"It’s not like peppermint schnapps," Leonard said. "What it is, or what they told me at least, is like a vodka, with spice or different herbs."


They kept drinking schnapps throughout the night, as they attended a professional soccer game between the Swedish national team and their biggest rival, Norway. Exhausted and jetlagged, Leonard slept easily in his pod bed that night.


Back in Austin, Taylor had to step into Leonard’s active, on-the-go lifestyle, despite a recent knee injury. He spent Saturday at the Texas-LSU football game and tailgate — probably the most American and Texan thing one could do — and then it was an early wake-up to meet members of RAW Running, Leonard’s running group, for a long run on Sunday morning.


View this post on Instagram

This was me 2h after I landed in America . I was standing next to two strangers but at the same time it felt that I had known them my whole life. I couldn’t contemplate what was happening but my soul said: "Go Staffan!" Thank you to all of you dreamers out there for sending love during this crazy trip that has changed my life in how I perceive opportunities. Every new day can bring us new magic, and every new day we can give away magic - if we are open for it So to you I say: "Gogo together we grow!" & also Go Americaaaaa! #yestheory #magic #sayyes #opportunities #friendship

A post shared by Staffan Taylor (@staffantaylor) onSep 27, 2019 at 8:17am PDT


The knee injury prevented Taylor from running a full 10-mile loop around the Butler Hike and Bike Trail, but his new teammates were game for a slow mile jog before literally picking him up and carrying him to the finish — which made for a fun outtake in the video.


The group gave Taylor a quintessential outdoors experience by hanging out at Barton Springs Pool, grabbing lunch at vegan hotspot Casa de Luz and canoeing around Lady Bird Lake.


"He was the perfect Alex replacement," said David Roses, one of Leonard’s running friends. "Staffan is a freakin’ bundle of positivity, and it was a blast hanging out with him. We talk all the time — I just Snapchatted him earlier."


There was just one more surprise planned for Taylor before he headed home. The Yes Theory crew arranged for him to give a speech to a group of entrepreneurial students at the University of Texas, fulfilling the Swede’s dream to speak to a group of Americans.


"I always wanted to get my words out there, and here I am, able to send out my positivity and the kindness," Taylor said in the video, wiping tears of joy from his eyes. "I am super happy."


Leonard’s trip to Sweden ended with a walking tour of Stockholm and a sunset pontoon ride, complete with "Texas-style" burgers on the grill.


The Austinite never actually got to meet the man who lived his life for two days, but they’ve chatted back and forth on Instagram. He thinks they’d get along just fine.


"I would take him out to face his fears through some type of physical activity — maybe climbing or skating — and I’m pretty sure he would want to do something social to push my boundaries. High-fiving strangers, speaking in public," Leonard said of his Yes Theory counterpart. "I think we’d push each other out of our comfort zones."


Taylor has parlayed his Yes Theory experience into several TV appearances in Sweden and more public speaking gigs. Leonard says his trip has had a positive impact on his physical therapy clients, and — he hopes — on himself.


"Over there, I just felt a lot more outgoing and more open to meeting people and just being spontaneous," he said. "Keeping that positive, open mentality going is the challenge that I’ve set for myself. I have to keep that ball rolling."