This painfully honest and often harrowing portrait of a highly creative man who has struggled throughout his life with both manic depression and paranoid schizophrenia is almost unique, the only comparable work being "Derailroaded", the story of the late Wild Man Fischer, another outsider musician with exactly the same mental health problems. The difference is that Fischer had zero musical talent, and very little archive footage exists of his brief D-list semi-fame as a dancing monkey in Frank Zappa's freak show before he was discarded again. From an early age, Johnston obsessively recorded everything he could about his life, initially on audio cassettes and 8mm film, later on grainy video when that became available, so we can see, or at least hear quite a lot of what was going on in his life at any given time instead of merely being told about it by a narrator. Also, unlike Fischer, Johnson has talent. He plays the piano extremely well; his voice, though not particularly good, isn't painful to listen to; and he can even write songs other people want to record in a non-ironic way.
The one major failing this documentary has is that it's taken for granted throughout by everybody that Daniel Johnston is without question a genius. Is he, though? Kurt Cobain thought so, or at least said he did, but that doesn't make it true. And a huge proportion of Johnston's cult status derives from the somewhat indirect fame he gained as the guy who made the album whose cover was on that tee-shirt Kurt Cobain wore in quite a few publicity photos, though since the actual record only existed as a self-distributed cassette, nobody knew what he sounded like. It's worth remembering that the album he eventually recorded as a result of all that publicity - his first and last with a major studio - was a dismal failure, selling less than 6,000 copies. As a lyricist, he's no better and probably quite a bit worse than many other quirky songwriters such as Robyn Hitchcock or Ivor Cutler; but of course, they never went authentically mad. And Daniel Johnston certainly did go very mad indeed! Wild Man Fischer may once have shat in a cupboard because he couldn't remember which room was supposed to be for that purpose, but he never deliberately crashed an aircraft in the belief that it wouldn't matter because he was Casper the Friendly Ghost!
The real power of the film lies in its account, much of it illustrated with videos taped at the time, of a sensitive, highly articulate young man utterly losing his mind, and never quite getting it all back. Johnston's actual music, surprisingly little of which is used in the film without interruptions or voiceovers, is infinitely less moving. However, as the story of an extremely minor musician descending into a terrible place most of us cannot begin to imagine and desperately trying to climb out again, it's tremendously compelling real-life drama. By the way, if you're slightly mentally unstable and you're wondering if this means it would be a bad idea to take LSD, you really ought to watch this film before you make your mind up...