Morgan! (1966)

Morgan Delt is a failed, irresponsible left-wing artist whose Communist parents own a fish-and-chips shop in downmarket London. He is also an aggressive, self-admitted dreamer obsessed with Karl Marx, gorillas, and stopping his beautiful wife from marrying his former best friend. He uses his rich fantasy world as refuge from external reality, where his unconventional behavior lands him in a divorce from his wife, trouble with the police, and, ultimately, incarceration in a mental institution.