Foreshadowing

This eerie item from Harper's Magazine:

From a November 10, 1962, letter by Rose Kennedy to her son, President John F. Kennedy, among 252 boxes of her notes and letters.

Dear Jack,
In looking over my old diary, I found that you were urged on one occasion, when you were five years old, to wish for a happy death. But you turned down the suggestion and said that you would like to wish for two dogs instead. So do not blame the Bouviers if John has similar ideas.
Much love, dear Jack.