The phrase “the moon is made of green cheese” is an old joke and proverb about gullibility, not an actual belief about the Moon’s composition.

Quick Scoop: What does green cheese have to do with the Moon?

1. It’s about being easily fooled

  • The saying comes from old folk tales where a simple, naive person sees the Moon’s reflection in water and thinks it’s a round cheese.
  • Over time, “the moon is made of green cheese” became a metaphor for someone who will believe anything, no matter how obviously wrong.
  • People use it sarcastically, like: “If you believe that, you probably also think the moon is made of green cheese.”

2. “Green” doesn’t mean the color

  • In this phrase, “green” means young or unripe , not literally green-colored cheese.
  • A “green cheese” is a fresh, not-yet-aged cheese: soft, pale, and often round, which visually echoes the Moon’s disk.
  • This double meaning reinforces the idea of naivety: a “green” cheese and a “green” (inexperienced) person both suggest something not fully matured.

3. Why cheese and not something else?

  • The Moon’s round shape and mottled, spotty surface reminded people of a wheel of cheese, especially varieties with holes or pockmarks.
  • Storytellers leaned into that resemblance to craft humorous fables where animals or foolish people mistake the Moon (or its reflection) for a cheese in a pond or well.
  • This image stuck so strongly that it became a recurring motif in folklore, children’s stories, and later cartoons and jokes.

4. From 1500s proverb to modern pop culture

  • One of the earliest written uses in English appears in John Heywood’s book of proverbs from 1546, where he writes that “the moon is made of greene cheese.”
  • Already back then, it was used tongue-in-cheek to mock the idea that someone could be that easily duped.
  • The phrase has since shown up in:
    • Children’s media and cartoons (e.g., classic slapstick shows and animated space gags).
* Satirical “science” jokes, like fake satellite photos with expiration dates stamped on the Moon.

* Occasional April Fools’ nods, including space-related jokes that pretend to “confirm” the Moon is cheesy.

5. Any tiny grain of reality?

  • Scientifically, the Moon is made of rock, not cheese, and its composition is well known from lunar samples.
  • A few writers have noted that the Moon’s cratered surface looks a bit like Swiss cheese, which helps the joke feel visually intuitive.
  • There’s even a playful claim that certain seismic or vibrational properties of “green cheese” are closer to those of Moon rock than to some Earth rocks, but this is used more as a curiosity than serious evidence.

6. How people use the phrase today (forums, “latest news”, trending

chatter)

  • In online forums and social threads, people still drop the line “the moon is made of green cheese” as shorthand for “this claim is obviously nonsense.”
  • It often pops up when debunking conspiracy theories or mocking wild ideas: if a story is as believable as the Moon being cheese, you shouldn’t trust it.
  • Language and culture blogs occasionally revisit the phrase to explain that “green” really means “young cheese,” which itself becomes a mini “today I learned” trend.

TL;DR: “Green cheese” and the Moon are linked because of an old proverb: a naive person mistakes the Moon (or its reflection) for a round, fresh cheese. The phrase evolved into a standing joke about gullibility, not a serious claim about what the Moon is made of.

Information gathered from public forums or data available on the internet and portrayed here.