"The legend that characters run away from their authors-- taking up drugs, having sex operations and running for president-- implies that the writer is a fool with no knowledge or mastery of his craft. The idea of authors running around helplessly behind their cretinous inventions is contemptible."
(Say what?? "Cretinous inventions"?? If my characters weren't so busy running for president, they might take offense at that...)
"Many of my characters are fools and they are always playing tricks on me and treating me badly."
--Jorge Luis Borges
"In a sense, you build a corral for your characters to run around in. The fence keeps them confined to the limitations of the plot. But where they run inside the corral is a function of each character's freedom to be what he/she wants within the confines of the plot."
--Ronald B. Tobias
"No surpise for the writer, no surprise for the reader."
Tell the truth: do your characters run the show? Do you like it that way or do you want to call the character version of "Nanny 911"? When was the last time a character really shocked you? Did you keep it in the story, or did it wind up on the cutting-room floor?