There was a rumor in the Soviet Union that The Beatles had secretly visited the U.S.S.R. and given a private concert for the children of top Communist party members. They believed the song "Back In The U.S.S.R." was written because of the concert. Actually, some fans still believe so.
In The Beatles "When I'm 64," Paul McCartney asks a woman if she'll still be there for him when he's 64. In 2006, he got his answer when shortly before his 64th birthday, he and Heather Mills separated.
Ronnie Van Zant wrote the Lynyrd Skynyrd classic "Gimme Three Steps" after making the mistake of dancing with a girl whose boyfriend was in the bar and probably had a gun. He asked for a 3-step head start.