Kevin Theis was a high school junior from Deerfield Beach, Florida—a drifting drama kid who hung with the stoners but still got good grades—when he found his first big thrill. It was 1982 and The Rocky Horror Picture Show cult was in full swing. Every weekend at a movie theater in nearby Hollywood, a bunch of square pegs and amateur actors would dress up like virginal Janet Weiss, hunchbacked Riff Raff, and that famously sweet Transylvanian transvestite Frank N. Furter to act out Richard O’Brien’s sexy, camp musical parody of sci-fi horror movies while the 1975 film version of it ran behind them. The audience would play along, performing an ever more complex series of actions and responses that included lots of talking back at the screen. They often drowned out the movie itself, but no one cared.

Theis went with friends one night, and according to Confessions of a Transylvanian (Berwick Court), a tasty new memoir written with Ron Fox, his response was immediate and visceral: “It was weird. Absolutely. Way weirder than I thought it would be, even. But not granny-in-her-bra weird. It was 16-year-old girls-in-fishnet-stockings weird.”

The experience changed Theis’s adolescent life—and, for a while, his name, as well. Signing up to be part of the onstage ensemble of “weirdos, losers, sexy chicks, fat broads, geeks, faggots, dopers, freaks, criminals, complete dorks and goddesses,” he couldn’t fess up to being a dorky Kevin. So he lied and told the director, mountainous Donny, to call him Jack—”a no-nonsense, rebellion-is-my-business type of name.”

The Rocky Horror phenomenon began at the Waverly Theater in New York in 1976 and by 1982 had spread to dozens and dozens of movie houses across the U.S., including Chicago’s Biograph. I remember audience members bringing bags full of props—rice, toast, umbrellas, squirt bottles—into the theater, all to be used at one point or another during the show.

That Theis took one look at this circus and wanted in isn’t surprising. He was, after all, a horny teenage outsider with an appetite for theater. What’s surprising, and seemed so even to Theis at the time, is how easy it was to join up (as a lowly extra at first, of course) and how readily he was accepted. Fox was already a member when Theis came along, seasoned enough to have originated the troupe’s rendition of Janet Weiss’s squeaky-clean boyfriend, Brad Majors. Under the leadership of the very laissez-faire Donny, this pack turned out to be the perfect haven for misfits.

It was also a great training ground for a stage career. Now a Chicago-based actor and director, Theis recounts the adventures and triumphs he had during his year and a half with the show: his rise from extra to emcee and then to various character parts—most notably those of Frank N. Furter’s two main rivals, Dr. Everett Scott and Riff Raff—and, equally important, his increasing credibility as a member of the troupe. Getting in turned out to be easier than earning respect from the other actors, many of whom had been working together for a long time.

Like many memoirs, Confessions doesn’t offer a single, unified narrative. Instead, it provides a series of stories, some connected to others and some standing alone. This gives it the feeling of an after-dinner conversation where old friends repeat their favorite war stories (and I suspect that’s basically how the book got started). Theis and Fox drew me into each vignette and kept me interested. Though it’s constructed out of disparate pieces, Confessions never feels fragmentary or random. Rather, it allows you to watch Theis develop as a person and as an theater artist.

Anyone familiar with Theis’s professional work (it’s not hard to become so: he’s playing the title role in the Oak Park Festival Theatre production of Shakespeare’s Richard III through August 25) can’t help but see the future actor in the ambitious, gutsy, but often terrified kid depicted in Confessions. Theis’s many accounts of preshow stage fright followed by triumph should be required reading for student actors. And anyone interested in starting a storefront theater might learn a lot from the authors’ detailed accounts of the Rocky Horror troupe’s rich, drama-filled offstage life.

Theis and Fox write with the fluidity of born storytellers—which isn’t surprising inasmuch as storytelling is the essence of theater. They left me wanting more, and that’s exactly how any performer wants to leave his audience. Another lesson Theis learned from Rocky Horror.