Ships That Pass In The Night Meaning

(idiomatic, by extension) Things which have no significant connection or commonality.

Example: 1922, P. G. Wodehouse, The Girl on the Boat, chapter 4:
  [H]e sat down and we got into conversation. There wasn't time to talk much. . . . We got along famously. But—oh, well, it was just another case of ships that pass in the night.
1996 January 7, Isabel Wolff, "Arts & Entertainment: How We Met—Charles Collingwood and Judy Bennett," The Independent (UK) (retrieved 19 Oct 2013):
  We very seldom work together on The Archers, we're rarely in the same episodes, so often we're ships that pass in the night.
2008, MaryRose Occhino, The Sign of the Dove, ISBN 9780425207314, page 135:
  They may have passed each other in the lobby or on the elevator of the building they worked in, but as far as I know, they never had the opportunity to even say hello. They were like two ships that passed in the night.
2011 July 15, Kim Bielenberg, "18 holes with the Holywood hero," Independent (Ireland) (retrieved 19 Oct 2013):
  At one point, Gerry McIlroy had two jobs, putting in a 100-hour week as a cleaner and barman, while his mother Rosie worked a night shift in a factory. . . . Rosie and Gerry were like ships that passed in the night.
1966 Feb. 9, James Reston, "Ships Passing In The Night," St. Petersburg Times, page 14A (retrieved 19 Oct 2013):
  [T]he central figures in the action seem vaguely unrelated to one another, like ships passing in the night.
1984, Susan C. Farkas, Changes & Challenges: City Schools in America, ISBN 9780937846957, page 129 (Google search result):
  "Education and business used to be like two ships that passed in the night," said Delaware Gov. Pierre duPont.
1998 October 26, Jennifer Dunning, "In Performance: Dance," New York Times (retrieved 19 Oct 2013):
  In "Episode"—the opening dance—choreography, music, performances and underlying apparent themes looked like ships passing in the night. Nothing connected until a solo danced by a prowling, sensual Christopher Bonomo.
1999, Janet Duitsman Cornelius, Slave Missions and the Black Church in the Antebellum South, ISBN 9781570032479, page 68 (Google preview):
  Ordinarily the missionaries' religion and the slaves' religion were like two ships that pass in the night.
2009 February 14, Richard Dawkins, "The Science Show: Interpreting Darwin's theory" (transcript of interview), (Australia) (retrieved 19 Oct 2013):
  As a connoisseur of enigmatic titles . . . the Gouldian title that gives me most pleasure is a joint paper, "Clams and brachiopods: Ships that pass in the night," in a learned journal.