This film has finally brought a fresh touch to Italian comedies and deserve to be a classic.
One could say that trip (or on the road) plot and the funny mental disorders story have been around for a while but those are metaphors for life in the most accurate way: sometimes you have to loose everything and have a journey to find what you're really missing.
Sticking to the movie the story is touching and softly funny (with some vulgarity here and there but in a good way) with twists that are really a surprise and some notable cameos.
The only weak point is the soundtrack and music not really proper in every moment.
Watch this movie and give yourself a pleasant 90 minutes (unless you have something really better to do).