Robin Williams initially intended to take a small role as a favor to director Bobcat Goldthwait, with whom he has been close friends since their days performing stand-up comedy together, but was so impressed with the script that he requested to play the lead instead.
In a poignant line in the film, Robin Williams' character states: "Suicide is a permanent solution for a temporary problem." Unfortunately, five years after the film's release, Williams died by means of suicide.
The newspaper vendor who hugs Lance. Novoselic is a rock musician, best known as the bassist of Nirvana. Furthermore, it is well known that Nirvana's frontman Kurt Cobain committed suicide and director Bobcat Goldthwait was a close friend of Cobain's.
The trivia item below may give away important plot points.
At the end of the film, Robin Williams dives into a pool naked. There is an almost full-frontal scene of him swimming toward the surface which is reminiscent of art for Nirvana's album Nevermind. It's also interesting to note that the image is of a baby being lured by money much like Robin Williams' character was being lured by money. Also, his character changes his story by telling the truth at the end implying the idea of "Nevermind." It could also be pun meaning that the words in the note and journal were never from his mind.