I wish I had enough knowledge to do this properly. The one lyric drift that has struck me in recent years is in "Wild Mountain Thyme" - I learned it, and heard it for years with "If my true love were to leave me, I could surely find another" until one day a friend mispoke while singing it and it came out "If my true love were to leave me I would surely find no other" this simple change revamped the whole song for me.