A childhood belief about songs

When I heard the song "Oh Susanna" as a very little kid I was very confused about the verse about coming from Alabama with "a banjo on my knee".I literally thought it meant the guy had limped a long distance with a banjo tied or strapped to his knee, which must have made his knee really sore and raw! My belief in this idiotic idea was further confirmed by my grandmother who for some reason didn't think it was very Ladylike to play a banjo.When she heard me singing the song ( we learned it it school) she commented sharply that she hoped she would never see me with a banjo on my knee.I quickly agreed with her.Who wanted to do anything as stupid and painful as to strap a banjo on my knee and go hiking to another state until my skin rubbed off? It was several years before I figured out the actual meaning of the song and the snobby attitude behind Grandmother's comment.