There are two possibilities here: either Dylan is a genius, or Dylan is the most psychologically screwed-up person in the history of the planet.
I suppose there is a third possibility: a very weird dude is blessed with real talent which thereby enables him to make weirdness and talent seem like genius.
This film embraces the first possibility. Instead of appraising the man and his impact the filmmakers chose to do an homage to his image. It’s an interesting take on a complicated dude. Well worth watching despite being absolutely interminable.