Michael Caine wasn't always Michael Caine. His birth name is Maurice Micklewhite and until recently, that was still his legal name. He finally, officially changed it to Michael Caine because of ISIS.

Getty Images

He said, "An airport security guard would say, 'Hi, Michael Caine,' and suddenly I'd give him a passport with a different name on it. I could stand there for an hour. So I changed my name."

When Caine started as a stage actor in Britain, he called himself "Michael Scott". Then he moved to London, where there already was a Michael Scott. So he had to change it again. He was a Humphrey Bogart fan, so he went with "Caine", after the movie "The Caine Mutiny".