Just in time for St. Valentine’s Day, “Dear John” is a love story based on the novel by Nicholas Sparks (“A Walk To Remember,” “The Notebook”). Judging from the popularity and solid romantic weavings of these earlier novels- to-movies, “Dear John” is going to be another favorite. John (super-cute Channing Tatum) is a soldier who falls for a college student, Savannah (Amanda Seyfried), while on a leave one summer. The chemistry is palpable and these two really seem meant for each other. But of course there are complications, and I don’t think I’m giving anything away when I say there is a “Dear John” letter involved. There’s really nothing earthshaking in the story or the relationship of John and Savannah, except that it’s refreshingly ordinary, and their blossoming, unselfish love includes other people: John’s reclusive Dad and a neighbor’s autistic son. There are different kinds of love here, all overlapping. Savannah kind of sets the tone for both of them. She’s a good girl, he’s a reformed brawler, but they’re not so different that they don’t quickly find common ground. These are two very believable characters and two very good actors, so it’s easy to get caught up in their tale. The direction is seasoned and seamless. There are no gimmicks, and not too much melodrama. No one likes being manipulated by movies, but what’s wrong with tenderness? Isn’t that what the world needs more of? Critics despise two kinds of movies — comedies and sentimental tearjerkers — no matter how much audiences embrace them. Is “Dear John” a tearjerker? Not really. But it does portray that kind of love that we all want (although the sacrificial aspects of their love are sometimes strained, outlandish, and a bit unfathomable). Actually, a weakness in the story is a never-satisfactorily-explained sort of faithlessness on the part of one of the lovers. The human heart is fickle. But we don’t want to be reminded of that. Not by Nicholas Sparks. The acting — especially on the part of Tatum — is inspired. Tatum masters a wide range of facial expressions and guymotions (guy-emotions) that make “Dear John” what it is. “Dear John” also reminds that unselfish love is really, really hard. Waiting can be really, really hard. In John Paul II’s “Love and Responsibility” there is an encouraging acknowledgment of this, and a philosophical dissecting of the same. There’s one pre-marital sex scene (not terribly graphic) and one “really bad judgment on the part of a married person” scene. It’s strange that sex scenes can still be PG-13, while three uses of just the “F” word warrant an automatic “R”-rating. Final verdict? Keep cranking ’em out, Sparks.