Santa is real in the same way that Uncle Sam is real. Each is a personification of an idea. Uncle Sam is the Spirit of America personified; Santa Claus is the Spirit of Christmas personified.
Saying that Santa Claus isn’t real is just as untrue as saying that Uncle Sam isn’t real. As long as America exists and Christmas is celebrated, they will remain real indeed.
Wonder what would have happened to the teacher is she would have said that Jesus does not exist?
I really like the way you put that. I agree 100%.