The speech of Greer Garson, Best Actress for Mrs. Miniver, was extremely long, thanking everyone, including “the doctor who brought me into the world.”
“I walked into the wings,” Garson later recalled, “and a man said, 'you spoke for five and a quarter minutes.'” The stately British thespian then realized she had broken “a sacred” rule, for “leading ladies aren't supposed to get further than, thank you, thank you, and burst into tears.”
Garson's speech soon became a joke in Hollywood, imitated to death at parties. Rumor has it that in the next decade Garson refused to speak in public at all. This kind of speech is impossible today, when every minute of advertising costs a fortune.
By comparison, James Cagney, Best Actor for Yankee Doodle Dandy (in which he embodied George M. Cohan), was more subdue: “I've always maintained that in this business you're only as good as the other fellow thinks you are. It's nice to know that you people thought I had done a good job. And don't forget it was a pretty good part, too.”
Cagney exited the stage with George M. Cohan's famous line: “My mother thanks you, my father thanks you, my sister thanks you, and I thank you.”