I had the pleasure of attending Diary of a Wimpy Kid: The Musical at Theatre of Youth with my favorite nine-year-old—who also happens to be a superfan of the wildly popular book series by Jeff Kinney.

Harbor Playhouse is staging a musical production based on the "Diary of a Wimpy Kid" book series. The show follows 11-year-old Greg Heffley's quest for popularity in middle school. Featuring a large ...