At one point in “It Started as a Joke,” H. Jon Benjamin recalls how he was first introduced to Eugene Mirman or rather Mirman introduced himself to him, belligerently stomping towards his table at a restaurant to pick up a half-eaten pork chop off his plate, taking a bite and declaring, “This is unacceptable” before stomping right back out before even uttering his name. It was love at first sight, the kind of bold, weird comic bit that might not have been everybody’s cup of tea, but certainly made him beloved among other comedians, though it’s a little hard to square with the gentle giant we see making eggs and playing around with his young son and his wife in Cape Cod at the start of Julie Smith Clem and Ken Druckerman‘s lovely and unexpectedly moving profile.

Mirman is no less fearless than he once was, but as “It Started as a Joke” comes to show, it was a different time in his life, one that’s coming to a close when Smith Clem, a longtime collaborator, turns on her camera to capture the 10th and final Eugene Mirman Comedy Festival, an event Mirman initially hatched as a spoof of other comedy festivals. With acts built around such topics as “Yikes! Half of These Comedians Were Born Before ‘Police Academy 2’ Came Out” and “I’ll Be Famous in Five Years (Or An Audience Coordinator for a Sitcom),” it became a serious event in the comedy world, even if nothing else about it was in giving the room to the likes of Kristen Schaal and Kumail Nanjiani to explore their wildest ideas, and as Michael Showalter notes in the film, Mirman didn’t only have a unique sense of humor, but a different attitude towards his profession than most others – in the wake of the comedian-driven sitcom smashes of the late ‘90s when most saw standup comedy as a stepping stone to a steady paycheck on television, Mirman was far more interested in building a platform than standing atop it.

That generosity is reflected in how “It Started As a Joke” isn’t much of a biography, though it eventually delve deeply into Mirman’s personal life, but instead a beautiful illustration of a cultural moment that was created together when you see pretty much every major present-day comedian working their way up from Mirman’s first foray in showcasing other comics, “Invite Them Up,” to the annual event at the Bell House in Gowanus. It would’ve been enough to simply play clips from past years and show a few routines from the emotional final show to make for an engaging documentary, but “It Started As a Joke” becomes far more, slyly ambitious in looking at this particular Petri dish for alternative comedy to ask what a joke can be and chronicling a time of real innovation for the form. One of the funniest scenes in the movie is simply having Michael Che show up for the festival to read off the premises for “Saturday Night Live” sketches he’s pitched that were rejected without much commentary and Janeane Garofalo is unsparingly candid in describing herself as a “filibusterer” instead of a joke-teller, with the film wisely devoting time to seeing how she feeds off the audience and vice versa during a conversational set.

The filmmakers honor the organic quality of what Mirman birthed with a poignance that sneaks up on you and even perhaps the performers themselves. Nearly half the comedians who show up for the final concert including Jon Glaser, Bobcat Goldthwait, Jim Gaffigan and Mirman himself say some variation on “I wasn’t planning to talk about this tonight” before launching into raw, stream of consciousness monologues that are both blisteringly funny and remarkably intimate in perhaps the ultimate testament to what comedy can be. Though you suspect Mirman’s inspiration hasn’t waned with a decade of festivals behind him, you can leave satisfied that there’s nothing left for him to prove and in giving audiences a peek behind the curtain, “It Started As a Joke” really makes it feel like you’ve been privy to something special, not only in terms of comedy, but in terms of the potential of people.

“It Started As a Joke” will screen at SXSW on March 14th at 8:45 pm at the Alamo Ritz 1.