When are you truly a fan? When the artist’s mediocre or spectacularly bad output is just as fascinating to you as his high points.

This is why, to we pathetic souls enamored of one Bob Dylan, the children’s choir on his version of Kris Kristofferson’s “They Killed Him” or Bob’s double-tracked version of Simon and Garfunkel’s “The Boxer” — to achieve the effect of a duet, you see — is just as fascinating as Al Kooper’s organ on “Like a Rolling Stone” or the clicking of Bob’s buttons against the base of the guitar on the long-unreleased version of “Idiot Wind.”

Which is why I’m so excited to see Bob’s new movie, “Masked and Anonymous,” which he supposedly co-wrote with director Larry Charles and has been receiving scathing reviews all around.

For example, in a column called “Bob Dylan Undone” in The New York Observer, Ron Rosenbaum writes:

In this case, the kindest thing I can say is this: Bob Dylan needs a friend. It’s painful (and a little cruel) to say, but that was my chief reaction to having seen Masked and Anonymous, not once, but twice.

Yes, I’m sure he has plenty of “friends” — all the people who told him his new movie was brilliant in concept and execution: “Don’t change a thing, Bob.” All the professors and poets who shamelessly sucked up to him with their praise. I’m sure they were really good friends. (And I’m sure there are some hardcore fans who will find the film fabulous.)

Maybe what I’m saying is that he needs a different kind of friend, the kind who could say to him, for instance: Don’t you realize how incredibly vain your pose of humility in this film makes you seem? Don’t you realize how silly it is to call your character “Jack Fate”? Don’t you realize that you’ve made several lifetimes’ worth of brilliant music? (Only a couple of instances of which are on the soundtrack.) You don’t need to make a painfully pretentious film that does nothing but diminish the respect the music deserves.

It should be fun! Even better — or worse — than “Hearts of Fire.” A man can only dream.