Prater Violet by Christopher Isherwood

This joins the list of the most perfect short novels I've ever read.

The rest of that list:

• Offshore by Penelope Fitzgerald 
• Human Voices by Penelope Fitzgerald 
• The Prime of Miss Jean Brodie
• Panama by Thomas McGuane
• Poor George by Penelope Fox
• Old Filth by Jane Gardham
• The Third Policeman by Flann O'Brien
• The Following Story by Nooteboom