It would have been amazing enough if he had lived without money for one year, as an exercise. Extraordinary if he did it for two, or five. But for 12 years? With no signs of stopping yet?
"I know it is possible to live with zero money," he says. "Abundantly."
He sleeps in caves in the Utah canyonlands much of the time, although he also house-sits. Once, he lived in a treetop for several months to keep loggers from it from cutting it down. He accepts meals from friends, but also goes dumpster-diving in search of discarded food that is still edible.
Doesn't panhandle. He occasionally works, but not for money.
He's been accused of being a mooch and a freeloader, but he doesn't see it that way. He accepts what is freely given - or what is discarded, in the case of picking clothes out of the trash - and he gives freely in return.
So although there's no money involved, there is nevertheless an odd sort of currency in his life.
Believing that things will somehow show up when he most needs them - and, oddly enough, they often do - he has relinquished control to chance. He says, and seems to really believe, that "everything happens for a reason."
And, to all appearances, he's happy. Indeed, happier than many.
I can't decide if he's incredibly complicated, or unbelievably simplistic.
Either way, in our world, Sundeen writes, someone like Suelo is utterly improbable.
"Suelo's quest to rid himself of money, when measured by modern yardsticks like politics and economics and psychology, just doesn't add up. People in the real world don't behave like this. The genre in which people wander for years in the desert, give up all worldly possessions, dwell in caves and survive a series of near-death trials, is mythology."
We're just not set up for this. As Sundeen writes, "Even lands set aside for the public do not welcome a man without money. While a company may drill a mine or erect an oil rig on federal property, a citizen is prohibited from building a cabin there."
A large part of the book explores not how Suelo lives now, so much as how he got to where he is.
His extraordinary life view is rooted in fundamental Christianity - although I have to confess that some of the discussion in the book seemed a bit esoteric. "For fundamentalists, living in a cave and eating locusts and wild honey is a less far-fetched way of life than it seems to secular people concerned with getting a good internship and scoring high on the SAT," Sundeen writes.
Suelo's life has been, in many ways, a life of disillusionment.
Despite his Christian upbringing, Suelo nevertheless came to question many of Christianity's tenets. He joined the Peace Corps and went to Ecuador, but concluded that the efforts of outsiders, including missionaries, to help the Indians there in fact harmed them by introducing the Indians there to the monetary system. "There was no poverty in the jungle until they introduced money," Suelo says. "And all the sudden there's poverty."
He became depressed. He tried to commit suicide - another bizarre event that even Suelo can't really explain.
He worked or volunteered at social service agencies, only to conclude that instead of making a difference in people's lives, they were disastrously rigid and dehumanizing.
The book is an interesting contemplation for anyone who has ever wanted to just chuck it all and take off - which is to say pretty much all of us, until we "get smart" or "grow up."
What Suelo provides is the counterweight to consumerism, greed and the corporatization of society. He's the one saying that the emperor has no clothes.
And even if we don't want to be like him, the story of his life will leave readers with persistent, itchy and unsettling questions about what life means and just how important money is or isn't.
The economic downturn, a voluntary simplicity movement, and Annie Leonard's The Story of Stuff have prepared us only a teensy bit for the likes of Suelo.
In the end, I didn't want Sundeen to stop. I wanted to know more about Suelo's life now, rather than so much about how he got there. What's a typical week like? What's the biggest challenge? What's the worst thing that's happened to him in his post-money life? What's the best?
He is aging, of course, and has no regular doctor or dentist. Sundeen asks about that. "It's one thing to forsake material goods like food and a home, or privileges like driving a car or flying on an airplane, but I wondered how far Suelo would take it. Would he get sick and die rather than compromise?"
"I guess that's where what people might call the superstitious, the religious part, comes in," Suelo tells him. "If we're following our path, then worrying about what could or should happen is a worse illness than what could or should happen. â ¦ I really don't know what I'll do, and I don't think about it that much. Some might call that irresponsible. But that's part of the path I'm on."
Sundeen meets with Brian Mahan, who once taught Suelo at the University of Colorado, and is an expert on the tension between worldly success and spiritual meaning. The professor says that he "never envisioned anyone being quite that radical." But he sees Suelo's quest as "a deeply moral act."
And rather than challenging Suelo, he says, "it is for all of us to answer why we question the Dans in the world."
Contact Sandy Bauers at 215-854-5147, email@example.com, or follow @sbauers on Twitter. Visit her blog at philly.com/greenspace