Nobody Ever Knows What Anybody Else Will Do

John Connolly, talking about the enduring appeal of the crime / mystery novel, expresses it best for me with the deliciously pithy, “Character is mystery.”
  I’ve come across two variations on that notion in the last week or so, in Raymond Chandler’s THE LADY IN THE LAKE and Ross Macdonald’s THE GOODBYE LOOK. Chandler first:

  “Nobody ever knows what anybody else will do, sister. A cop knows that much.”

  And Macdonald:

  “That was good timing,” she said to me. “You never know what George is going to do.”
  “Or anybody else.”

  All of which makes a mockery of the rule that people should always behave ‘in character’ in novels. If everyone always behaved as they should, life and fiction would be very boring indeed.