This is actually a fairly common occurrence. There’s a phenomenon called mondegreens, It means, “a word or phrase resulting from a mishearing of another word or phrase, especially in a song or poem”.
The phrase came from an American writer by the name of Slyvia Wright, and written about San Francisco Chronicle columnist Jon Carroll. Mondegreen is inspired by a misheard line in a poem. She misheard “he laid him on the green” as “Lady Mondegreen” from the Scottish ballad “The Bonny Earl o Moray”.