The unrated trailer for Leaves of Grass, a pot comedy (get it? GRASS.) written and directed by Tim Blake Nelson starring Edward Norton as two very different brothers — one’s an Ivy League professor, one works in, um, horticulture — didn’t actually make me laugh that hard the first time I watched it. But upon repeat viewing, I started to get it. The characters need to grow on you a bit. Nelson wrote the part with Norton in mind, and he seems to be having a high time playing the bad boy. But I still prefer my Ed Norton a bit nerdy and exasperated: “Pull the trigger. Put a bullet in my skull.” You?