"On August 17, 1955, Elvis Presley released what would become his first No.1 hit, 'I Forgot to Remember to Forget / Mystery Train'. It hit the top of the country charts several months later and stayed there for 5 weeks."
I never heard this one until well after he was a Rock & Roll hit. The wife of one of my flight training classmates was a DIE HARD Elvis fan and she had this song in her collection.