Asked the inevitable question, “Are you excited?,” some of the Academy Award nominees were cool, proud, even nonchalant. “I’ve got to start a movie in three days, and I’m more worried about that,” Billy Bob Thornton told reporters this week at an Oscars lunch in Beverly Hills. Nominated for best supporting actor in “A Simple Plan,” Thornton added: “It is exciting. I’ve been around 20 years, and I feel real good about being nominated.” Australian Cate Blanchett, nominated for best actress for “Elizabeth,” said she was “enormously excited” and joked that “per capita, Australia has the highest number of nominations.” Rachel Griffiths, a best supporting actress nominee for “Hilary and Jackie,” quipped in her response: “No, I’m used to it. I’m just waiting for lunch.” The awards will be given out on March 21.