It's a uniquely American thing, alex. It's a day when we ought to thank God for what we have, but has devolved into pigging out and watching football. (No, not your football.) But it is a time to gather into families and celebrate that we have families.
It is reunion day. Get the scattered family back together day.
It was Lincoln who decreed (executive order) that the last Thursday of November ought to be that time of national observance was to be Thanksgiving day.