Russell Brand stars in Jason Winer's reboot of the 1981 Dudley Moore comedy about a rich man who refuses to grow up. He parties, cruises around Manhattan in ridiculous cars, and leaves it all for his stalwart nanny, Hobson (Helen Mirren), to clean up. Then, Arthur must man up when his mother forces him into an engagement with a social climber (Jennifer Garner) at the very same time he meets a free-spirited tour guide (Greta Gerwig). It's an unnecessary remake, designed to showcase Brand's loutish (if, here, PG-13) style of comedy. It lurches, much like one of Arthur's souped-up cars, from vulgarity to sappiness, and most of its jokes you've seen in the trailer. Dame Mirren is game in the role originated by Sir John Gielguld, though I can't help wondering whether her participation here wasn't the result of some late-night bet decades ago between these two well-respected thespians.