Why do we have Goose at Christmas..?
Evolution has designed the bird so that it's tender and ready to eat at eight or nine months old, and since it hatches in spring, Christmas is the best time to 'gobble' it (forgive the pun..)
The goose is a solar bird, and the tradition of eating it at this time of year is as old as the pagan sun festival onto which Christmas piggybacked when it reached the British Isles. When the harvest was done, geese would traditionally roam over the stubble-plains and fatten on fallen corn; windfall apples could be made into sauce, and sage dried from the summer was perfect for a stuffing.
Once you start noticing, there are many lovely synchronicities between the passing of the seasons and the rumbling of stomachs...