The title of an interesting essay by Sigismund Schlomo Freud.

Although it often seems difficult to believe, Freud spent a distinct portion of his professional life investigating paranormal phenomena.

Rebecca A. Drayer, "Freud's Studies of the Occult"

The subject of Freud's essay is the strange thing that often happens when you go see a fortune teller or palm reader or what have you. They often make a prediction that has some element that is highly personal and meaningful to you, although the prediction doesn't come to pass.

An example that F. gives concerns a male patient who was sexually obsessed with his [female] cousin. This cousin happened to be married. The patient told Freud about a visit to a palm reader earlier the previous year. The visionary told this man that his rival in love would die the following summer of food poisoning after eating a dish of clams.

Freud was quite irritated by the relish with which the man related the prediction, and he said, "Well, so what? The summer has come and gone, and the man is still alive!"

"Yes," the patient replied, "but he is allergic to clams!"