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.