Jack Lucas (Jeff Bridges) is a late night disc jockey for a radio talk show and is renowned for saying exactly what he feels, and hoping that they don't take him too seriously.
However one evening he inadvertently convinces a caller (who just happens to be a sociopath) to blow up restaurant patrons and then himself.
On hearing the disturbing news the following day Jack wallows in his remorse, which lasts three years. After this time he is attacked and almost set alight when a crazy homeless man named Parry (Robin Williams) rescues him from these tormentors and befriends the now suicidal DJ.
Jack tries to reward Parry for helping save his life with money, but Parry's only wish is for him to join him in his quest for the Holy Grail!
It isn't long until Parry tells Jack that he was a history teacher and married at one point, until his wife was killed in the restaurant blast, an obvious reason for his lunacy now.
With this knowledge Jack bends backwards tohelp Parry and soon learns that the penny compassion or sardonic love of the working world isn't enough to live on and what friendship entails, namely, is a little craziness and a lot of struggle for moments of shared happiness.
A wonderful film of self discovery.