More importantly, the concept of his story wasn't implausible either: As tuition costs have skyrocketed, it makes sense that people might try to siphon off some of the benefits of college without paying. While the specifics of what Dumas told me may be hard to confirm, the fact remains that a young adult could conceivably infiltrate a college campus without paying tuition. What might this say about the monetary value of a diploma? And can its component parts—learning, socializing, networking—be unbundled? If so, what would remain?

According to his friends, Dumas is something of a free spirit, and as a teenager was rarely seen without his longboard. His parents didn't insist that he go to college, but Dumas says he began his higher education because he thought he wanted to be a psychologist. He enrolled at a city college in his native Quebec in the mid-aughts. “I started college at 19, and I did that because that's what everybody does,” he says. He started on an academic track to earn a degree in psychology, but he was too intellectually omnivorous to stick with a single discipline.

So he began taking classes in which he wasn't enrolled. “I was just sneaking into classrooms in literature and philosophy and poli-sci and even psychiatry,” he says. Soon, sitting in on classes he wasn't signed up for started to feel natural. “I just found out how to do it. When to hide. What kind of alibi to have or to behave with other students—what to tell, what not to tell,” he says. He erred on the side of staying secretive.

Dumas started taking classes at other campuses nearby: Concordia University, University of Montreal, and McGill University. He started thinking bigger. Providence, Rhode Island, the home of Brown University, was fewer than six hours away by car, and New Haven wasn’t much farther. Dumas says he attended Yale in the spring of 2009, couchsurfing for about a month, and he spent time at Brown too. He says he was taking classes and spending only a few hundred dollars a month, most of it on alcohol for parties. When he later went to UC Berkeley, where he lived at a campus co-op for about two months, his expenses were larger—$600 or $700 a month, in his estimation. While at these schools, he reaped most of the perks of college: learning, partying, and meeting intelligent, like-minded people.

Full tuition at Yale for the 2014-2015 school year, which includes room, board, and books, is $63,250. This breaks down to a little over $7,000 per month during Yale’s academic school year, which means Dumas was getting most of the selling points of college at about a tenth of the cost. At Berkeley, average tuition (which includes in-state and out-of-state students) is about $28,000, but that still works out to more than $3,000 per month. Of course, many students at both colleges receive some form of financial aid, but these are the sticker prices of diplomas there, and many students pay them in full. (This is especially true of international students, who have a much harder time qualifying for financial-aid packages.)