That rarest of breeds — the fantasy film for grown-ups. Director David Fincher (Se7en, Fight Club) and screenwriter Eric Roth (Forrest Gump) adapted this 159-minute feature from F. Scott Fitzgerald’s jokey 1922 story about a man who’s born elderly and over the course of his life ages into a baby, but they’ve turned it into a gravely beautiful drama about the mysteries of aging and death. Brad Pitt (there’s tongue-in-cheek casting for you) plays the title character, whose stunning metamorphosis from codger to brat is accomplished through a combination of prosthetic makeup and digital manipulation. Cate Blanchett plays his one true love, and the story’s richest, darkest irony is that she and Benjamin are made for each other yet painfully mismatched for all but a brief period in their lives. With Taraji P. Henson, Julia Ormond, Jason Flemyng, Elias Koteas and Tilda Swinton. Rated PG-13.