The personality types of both characters/egos are spot on at capturing the almosted cliched stunted development/fringe lunacy that rock players tend to have...
Also the whole deal with the pick, aside from the quasi-superstitiousness players feel about their picks (especially early on) was a great way of (lovingly) taking the piss out of the early stages of playing where you think that its different guitars and hardware (even picks) that make Slash sound like Slash, make Jimi sound like Jimi and Hetfield like Hetfield... its fallacy to a large extent, as what you are playing and how YOU are playing it.
'This is Spinal Tap' was another that was great at working with these archetypal personalities/story arcs and deilivering solid laffs along the way.
Here would be a challenge...
Watch and remember both movies.
Learn even a little bit of whatever instrument and joining a band, playing for just one year:
And try not to inadvertantly fall into any of the situation types/cliches in either film at some point lolz.