How famous did “Wet Hot American Summer” make Michael Showalter? Underwear famous.

Describing a recent attempt to return some Tommy John merchandise he ordered by accident, Mr. Showalter said that at the end of an email exchange with a customer service representative, “They wrote, ‘If by any chance you are the Michael Showalter from “Wet Hot American Summer,” I very much look forward to watching the new episodes on Netflix.’ ”

Even this much celebrity is more than Mr. Showalter and David Wain could have expected some two decades ago when they started to write “Wet Hot American Summer,” an absurdist period comedy about an ensemble of misfit counselors living it up on their last day of camp in 1981.

Despite its willful goofiness and a cast that included young talents such as Amy Poehler, Bradley Cooper, Elizabeth Banks and Paul Rudd, all soon-to-be stars, the film was a flop upon its 2001 release.

Fourteen years later, it has found a sufficient following — not just among undergarment makers, but a small though intensely loyal audience of comedy fans — to spawn a prequel series, subtitled “First Day of Camp,” which Netflix will release on July 31. The series accomplishes the seemingly impossible task of reuniting the film’s cast — those who achieved A-list status, those who once had it and those who never came near it.