Maybe I read too many of John Powers’s Catholic-school memoirs in junior high, but Courtney Shaughnessy’s look at a parochial middle school circa 1987 feels mighty derivative. The play draws on a hoary device: New York writer Mikey Owens returns to his midwestern hometown after his mother’s death and explores the experiences that marked him, all of which revolve around the year he spent at Saint Peter’s refusing to speak after his father died. Adam Belcuore’s Mikey is charming, and in Michael Matthews’s staging for Serendipity Theatre Company, the cast adeptly navigates the script’s switches between the characters as kids and adults. But they don’t emerge as much more than carefully drawn stereotypes, and the Catholic-centric humor has been played out in numerous other shows. Despite the play’s heartwarming moments, Shaughnessy’s sentimentality often turns Being 11 into a treacly version of The Wonder Years. Through 12/18: Thu-Fri 8 PM, Sat 5 and 8 PM, Sun 2 PM. Athenaeum Theatre, third-floor studio theater, 2936 N. Southport, 312-902-1500. $16-$17.