Too many to name, aidan. There are songs that I know and don't know why I know them. I feel that it has to do with family tradition. From my Mom, ragtime; from my dad; strange songs like, "Don't Let the Deal Go Down." and "The Old Apple Tree in the Orchard."
From my brother, lots and lots, although I never got to know him. I now depend on my older sister to remind me.
Make of it what you will, but I think it has to do with RNA from the womb, and I'm serious about that.
Example is knowing the words and hearing the melody to "..And Mimi.." Stunned when I heard Al Jolson sing it, and I searched and searched for the reason.