Why do people say the moon is made of cheese?
The origin of the term “blue moon” is steeped in folklore, and its meaning has changed and acquired interesting meanings and nuances over time. The earliest known usage was in 1362, in a pamphlet entitled Read Me and Be Not Wrothe: “Yf they say the mone is belewe, we must beleve that is true.” (If they say the moon is blue, we must believe that is true.) This implies the expression had a meaning of something that was absurd, and bears a close resemblance to another moon-related adage first recorded in the following year: “They would make men beleue… that beleve the Moone is made of grene chese.” (They would make men believe…
