Conversation so far:
When did Stirling Moss return to racing?
Although ostensibly retired from racing since 1962, Stirling Moss did make a number of one-off appearances in professional motorsport events in the following two decades.
Where did Stirling Moss compete after he returned to racing?
Stirling Moss competed in the 1974 London-Sahara-Munich World Cup Rally in a Mercedes-Benz.
Did Stirling Moss win when he returned to racing?

Question: Why did Moss leave racing?
Self-contained rewrite: Why did Stirling Moss leave racing?