I love buckled hats. Many images in my mental "Thanksgiving" file include Pilgrims wearing buckled hats. Not only their hats, but their story-coming to a strange land, losing many of their friends to disease or starvation, receiving help from the indigenous peoples, and expressing their gratitude for that whole journey-is compelling.
Of course, the first North American Thanksgiving was nowhere near Plymouth Rock--Europeans settled in Virginia a century earlier, and Norse sailors arrived in Nova Scotia, several centuries prior to that--and they were all grateful to find food. More importantly, the indigenous peoples, those of the First Nations, had been expressing their thanks to the Corn Mother (and other symbols of natural benevolence) long before any Europeans arrived.
It doesn't matter who was first; what matters is that we *do* remind ourselves of the good things in our lives. Human beings operate by contrasts; our happiness is measured by comparisons. If we compare ourselves to our rich neighbors, or to the deliriously happy folks in TV commercials, we'll feel less fulfilled. If we are mindful of the blessings we do enjoy, we'll feel better about our situations. We don't have cool buckled hats, but we do have full bellies, and modern medicine, and our families and friends.