Bo Burnham’s Eighth Grade (B+) is so knowing it hurts. The comedian turned writer/director’s darker than expected feature debut is a canny you-are-there coming of age story. It follows a painfully shy middle schooler, magnificently played by Elsie Fisher, who struggles with the everyday challenges of her final days of classes on the precipice of a hopeful metamorphosis before high school arrives. A framing mechanism of the girl’s confident YouTube explainer videos pairs nicely with the awkward foibles of her altogether unremarkable real life. A highlight of her retreat into the social media void is a montage amusingly underscored with Enya’s “Sail Away.” Josh Hamilton, a Gen X staple, helps make an endearing film even more human as her resilient single father, who delivers an encouraging fireside chat that may move some to tears. The astonishing young Fisher’s raw, unglamorous turn as the protagonist anchors the film; and even when some of her character’s actions are head scratching, her every move is extraordinarily authentic. Burnham presents an assured filmmaking style with some brilliant point of view shots steeped in incredibly poignant milestones: trying to fit in at a pool party, holding “food court” with older kids, sitting through sex ed class and making small talk on a first date. It’s occasionally comic with an unsettling tone; few profound details evade Burnham’s candid camera. This is one of those low plot, high feel movies. It finds its heart as it finds its way.