Here’s a story for you: This part-time teacher whittled away at generations-old math problems on his own time, solving a puzzle that had eluded mathematicians for 150 years. Yitang Zheng, profiled in the New Yorker here, untangled the “bound gaps” problem of prime numbers, winning the prestigious MacArthur award among other prizes. At the time, he was teaching calculus part time. Previously, he’d done accounting for a Subway franchise.

There’s a romance about such an effort, which is I suppose why these stories of solitary mathematicians surface in the media from time to time. It’s interesting, inspiring — maybe even a bit troublingly weird — which are all cool things.

Mathematics has been called the purist science, and this sort of solitary, in-the-cabin (not necessarily an actual cabin) pursuit seems like the purist of scientific pursuits. It’s the purest of the pure. It’s like farm-fresh milk bathed in hand wash. (Does that metaphor work?)

It’s appealing because it revives the archetype of the lone-genius scientist, a fiction that’s harder and harder to maintain in an era of increasingly obvious cooperation and interdependence. You can’t be the dilettante, nobleman scientist of the 1700s, exploring the universe with a set of beakers in your parlor, when today’s scientific questions require billion-dollar behemoth machines that smash protons apart. Frinstance.

Even the theoretical side of physics, where Einstein worked, and which was long considered the purist (i.e., most mathematical) of physical sciences, isn’t so solitary. It generally happens within universities, these huge institutions, involving collaboration with colleagues, advisors, review boards, journals, peer reviewers, grant providers, administrators, savant janitors, etc. Even that frazzle-haired icon of scientific genius himself was much less of a lone explorer than popularly portrayed. Einstein probed gravity and time with his thought experiments, but relied on math developed by others to create his theories — something his (enduring) celebrity obscures.

But mathematicians! They can be the magi and (sorta-weird) loners we like to imagine. There’s romance, curiosity — and even a little judgement — involved with such figures. And these are all pleasurable feelings to experience. Remember the Unabomber? I do. I remember the fascination of the media, and of myself, with this mad professor/mathematician turned criminal. It made for a great story (and yes, an uncomfortable one, being that he mailed bombs and killed people).

Zhang’s story is not so uncomfortable, of course: he’s not a criminal. The only things he has in common with Ted Kaczynski are a talent for mathematics and a solitary devotion to his pursuits. But, quite opposite to the mail-bombing hermit, Zhang did not give up his mathematical devotions for something darker or kookier — or, in fact, for anything else. He stayed devoted to them, ultimately, without the support of a tenured academic position — i.e., without those big institutions that support so much of modern science and academics.

Zhang pursued the bound gaps proof while teaching basic courses in calculus at the University of New Hampshire. So, what motivated him? Zhang was working in “pure mathematics,” not the applied sort. He himself said that his proof was “useless for industry,” while others said that it had “a renaissance beauty.” The thrill of the puzzle, then, and the beauty of an elegant proof, seem to be the sole motivators. Zhang labored for years handling the books for a Subway franchise. He was a numbers genius, associates said, but had been unable to publish or get an academic post, so he’d mostly given up on his mathematical dreams.

Eventually, in a rare case for the field, Zhang achieved success in middle age. He wasn’t able to pursue his passions until a friend helped him find a job teaching calculus — clearly a very elementary use of his abilities, perhaps not much better than doing accounting for a sandwich shop. But it gave him the time and financial stability, maybe even the self-respect of knowing he was an academic again, that he needed to do his passion project. So, really, this is less the romantic story of a lone genius than a demonstration of the difficulty of such a path, even in the purest of sciences. Zhang might have found his proof much earlier, or at least much easier, if he’d had the support of a major institution — that is, if he hadn’t been forced into the “lone” part of the “lone genius” schtick.