I sing and hum. A lot. And oftentimes I catch myself humming one of about three or four songs. I call them my default songs and I've been singing/humming them my entire life. They are: Yellow Submarine; Peter and the Wolf; and God Save the Queen. (I think there's one more, but I can't think of it right now.) I have no idea why these are my defaults. I find the first song annoying, and I'm not even British. I really only like the second one. So truly, why these songs? I suppose it could be worse. I could be cursed with "Feelings." Gads.
Do you do this too? What are YOUR default songs?