Someone else’s fool is a joke, your own fool a calamity.

A folk proverb quoted by Solzhenitsyn.

Popular delusions occur when appealing but baseless stories spread contagiously from one person to another. Some ideas are more virulent than others: people have been found to react most enthusiastically to narratives of fear.

Edward Chancellor, "Waiting to Deflate" New York Review (August 19, 2021)