Christmas recital

I am playing in the recital next week. Usually I'm just watching everyone else. I have one Christmassy song to play and I need to know it well enough that the playing for an audience thing doesn't make me forget all the notes. It's funny the way that works. Despite being a full grown adult who has day through many lessons and been audience for lots of my kids recitals. Then it's me who has to play and it's right at square one that I am standing.