The following quote is often attributed to Mark Twain. But there is no evidence Mark Twain ever wrote this phrase, despite the fact his writings were very well-documented.
“It’s easier to fool people than to convince them that they have been fooled”
Flat-Earthers like to use the quote to ridicule & describe those who understand Earth is a sphere. In an ironic twist, by attributing the quote to Mark Twain, these flat-Earthers demonstrate that they are being easily fooled themselves.
The quote might have been invented to mislead those lacking critical thinking to spread it without realizing it is a fake quote. Then, the irony becomes a joke to everyone else.
Flat-Earthers are not known for their critical thinking skills. They are often misled to spread the quote, unknowingly announcing their critical thinking skills —or the lack thereof, to the entire world.
We can say the quote is a much subtler version of “Don’t believe everything you read on the Internet just because there’s a picture with a quote next to it,” with a photo of Abraham Lincoln next to it.