In the last few weeks, I have listened to a podcast that shed some new light on this song.
It seems that the "Merry Little Christmas" is a reference to the fact that this was written during the second World War. The line that says "Until then we'll have to muddle through somehow" was changed by Mr. Frank Sinatra to "Hang a shining star upon the highest bough" to brighten it up a little bit by the time the 1950's rolled around.
I love little stuff like this. Adding a historical context to that which is well-known and accepted does this teacher's heart some good.
I hope you are all having yourselves a happy little break so far, one day in.