“Six days, six weeks. I doubt six months,” said Donald Rumsfeld, on February 7, 2003, about the duration of the Iraq war. “Whatever happens in Vietnam, I can conceive of nothing except military victory,” Dwight D. Eisenhower said in 1967. Four years before that, Robert McNamara asserted, “The war in Vietnam is going well and will succeed.”

Mark Twain was born on November 30, 1835—two weeks after the perihelion of Halley’s Comet. “I came in with Halley’s Comet,” Mark Twain commented in 1909. “It is coming again next year. The Almighty has said, no doubt, ‘Now there are these two unaccountable freaks; they came in together, they must go out together.’” He died on April 21, 1910—one day after the comet had once again reached its perihelion. 

On July 23, 1995, in New Mexico, the astronomer Alan Hale saw an unidentified fuzzy object in the sky. He emailed the Central Bureau for Astronomical Telegrams. In Arizona, Tom Bopp saw the same thing. He telegrammed the bureau. The comet was named Hale-Bopp the following day. Believing that a UFO was traveling behind it, thirty-eight members of The Heaven’s Gate cult committed suicide on March 26, 1997, six days before the comet reached its perihelion. 

While on his deathbed in 1849, the Japanese artist Hokusai said to those gathered around him that he wished he could live another ten years. He paused, and went on: “If I had another five years, even, I could have become a real painter.” Then he died, at the age of eighty-nine.

“Where were you last night?” Yvonne asks Rick Blaine, played by Humphrey Bogart, in Casablanca. “That’s so long ago, I don’t remember.” Her follow-up: “Will I see you tonight?” To which he replies, “I never make plans that far ahead.”