I think I finally GET the movie!

So I had a thread on here before about the film's plot being completely nonsensical, but I think I just got it. Haven't watched it in a bit so I could be wrong, but was listening to Metallica.

A lot of people responded that there is no real plot and its just cool drug induced action to go with the music resulting from the pill he took in the beginning of the film. But could that be the point?

In the end we see he's at peace and everything is awesome and he gets his own cool Metallica show once he's sobered up. A lot of Metallica's music is just a metaphor for being self destructive drug addicts, so could the movie be trying to give the same message? That if you sober up everything is cooler and easier? Again I haven't watched it closely recently but thought I might have something with that thought.