This film's premise seems to be that the passing of the World War 2 generation in America, with its apple-pie phoniness and hypocritical morality, was a terrible tragedy. Those awful hippies ruined everything apparently.
What holds the film together are the excellent performances - particularly Lemmon's which is truly remarkable. Otherwise we have a boring slice-of-life drama (just over 24 hours of Jack's life) with pretensions.
I found it a chore to sit through.