The Dude has been a big music fan since the 60's - however , somehow he seemed to have missed Metallica.

Then  a few years back - one Friday night (after some beers with office chinese compadres) the Dude arrived home and kissed his good lady wife good night....

( she was working early the next morning as a nurse) and went to a empty lounge.
 
For reasons even the Dude is unsure of, he had in his possession a Metallica DVD entitled "Some kind of Monster”.

The Dude abides...

The first impression of the film was surprise - that these tough rock stars seemed to be struggling with the very basics in life.
The Dude was taken in by the rawness of the drama.  

Also, the Dude found himself very slowly appreciating the music element as well - Guitars were great!

Towards the end of the movie it is still unclear how James Hetfield

would respond to the rehab work. 

His life was just opened up and spilled across the screen in such a forthright way. Also, See The Separation.

The real hero of the film (and the reason why Metallica has survived so long is the energy of one person) ... IMHO - is guitarist Kirk Hammett 

Kirk has this wonderful ego-less nature to him and encourages the others with his energy.
Ultimately it is because of him that the members all able to come together.
He is the spiritual glue that keeps this group together.

Other Kirk qualities (i think) are that he is non-judgemental of Lars and James, he was not attached to any of the drama (past or present) - he is totally accepting of "what is"