I once was hiding out from the rain at the Old Songs Festival a LONG time ago, and Jay Ungar was there. I told him I could immediately play it, the first time I heard it (in a session - never saw the Ken Burns program before then). I told him it felt like he plucked that tune out of some collection of all the music that ever existed. I still feel that way - the tune was just always there. It's probably the same reason some people are sick of it the first time they hear it. (Haha)