The 2009 science-fiction movie “Mr. Nobody” evaded our radar during its initial release. Now it’s on our very slim shelf of films “worth watching again.” Directed by Jaco van Dormael and starring a precociously talented Jared Leto, “Nobody” has a central story — a boy on a train platform who is made to choose between divorcing parents — and a clever conceit — Nemo Nobody is the last living mortal (120 years old) in a society of immortals. But this film’s intense pleasure is in visual, narrative, and philosophical digressions that miraculously lead back to the plot. It’s a work of magnificent imagination and virtuoso technique. “Mr. Nobody” recalls the Coen Brothers at their best.