Have you ever seen any of these films: Kids, Gummo, Ken Park? They're all by the same director (Harmony Korine).
It's Dogma 95 certified but doesn't "jump" like films like The Idiots (Lars von Trier) or The Celebration (Fredrik Vinterberg). In Julien Donkey-Boy there are long scenes, but sometimes it's like a rapid slideshow of images with deliberate out-of-sync sound. A central theme of the film is schizophrenia, and the film really succeeds in depicting this.
This is not the kind of film you have dinner to whilst watching. It's revolting and disturbing but you can't stop watching and it really gets your brain going. Not like The Usual Suspects or Groundhog Day, where you think back at the details.
"He laughs, hysterical, then assaults his companion with a rock. Drooling and dripping snot from his nose, the young man looms over the camera, as if he has assaulted you with this rock, as the companion positioned as you lies battered beneath him. You're five minutes into the movie, and already you're feeling exhausted."
Read this review after you have seen the film.