I did grow up in a "singing family", which may have helped
Allon Gay Bergeres "Come, happy shepherdesses", Guillaume Costeley (1530-1606).
It's a beautiful little Christmas carol -- but it's tough because it does things that modern music doesn't do, and it goes FAST. If you so much as pause to say to yourself, "Oh, (*&^*^%*^~!" you are instantly 2 measures behind and will NEVER catch up.
Not to mention that it's sung in archaic French . . . and I don't even speak modern French.
If people sang more, easy stuff like the NA wouldn't seem so hard to them. For heaven's sake, just sing along with the RADIO!