Never thought much about this, Irene. What do I often sing, and perhaps a happy song, too? It has to be "You Are My Sunshine". I sang it with my grandmother who was a good pianist and sang with us often. I sang it to my children, and to the grandchildren.It comes along when I need it. Thanks for the invitation to think about this! And, FYI, at Christmas, I do sing Joy To The World a lot!
That's a lovely default to have, Irene!