moon (is) made of green cheese, (and) the

The most ridiculous thing imaginable. This farfetched figure of speech dates from the early sixteenth century. Despite the opinion of one collector of proverbs, F. E. Hulme (Proverb Lore, 1902), who believed it referred to the newness (“greenness”) of the moon each month, it has always been used as an example of outrageous absurdity.