Big-lunged lovers Allie (Rachel McAdams) and Noah (Ryan Gosling)—pampered Southern debutante and rough-earth mill worker, respectively—are on a freedom spree: lying down in the middle of the main drag late at night; getting aviary without the aid of hallucinogens (“Say I’m a bird!” Allie shrieks at her stud muffin. “Now say you’re a bird too!”); daring their teen romance to conquer time, distance, class, family meddlings, World War II (which the film renders as a brief skirmish played out in somebody’s backyard), and some inconvenient significant others picked up like lint along the way. The minutes of Allie and Noah’s magical hysteria tour are duly recorded in the titular ledger-cum–framing device, these days in the possession of a kindly codger named Duke (James Garner). He reads from the notebook to the now elderly Allie (the director’s mom, Gena Rowlands), who’s sadly befogged by an Alzheimer’s-like illness. Amid the sticky-sweet swamp of Jeremy Leven’s script (adapted from Nicholas Sparks’s novel), Rowlands and Garner emerge spotless and beatific, lending a magnanimous credibility to their scenes together. These two old pros slice cleanly through the thicket of sap-weeping dialogue and contrivance, locating the terror and desolation wrought by the cruel betrayals of a failing mind.