why an orange?

I have always wondered why the orange is a symbol of Christmas.  Why do we use it to decorate?  Why do the grocery stores seem to overflow with them at this time of year?
I did a little research and it turns out that many years ago, oranges were given as special gifts to children.  They were a rare commodity and sometimes the orange a child received Christmas morning was the only orange they ate all year!!!!

Is there anything we can only afford once a year?
Something to think about.