Memory links the present to the past, and the deliberate recall and recounting of past benefits is itself a form of gratitude. Civilization, and culture generally require memory and tradition. The latter (literally, from the Latin, ‘a handing on’) means a kind of gift, from what has been learned through experience, from the past to the present. The society that now accepts the gift is therefore ‘grateful’ to the past.
Margaret Visser, The Gift of Thanks: The Roots and Rituals of Gratitude