In Mexico today it's the annual Day of the Dead, when
people celebrate the lives of family members and friends
who have died. According to my advisers, there is still
some kick to the ancient belief that the souls of the dead
return on November 1 (All Saints’ Day) and November 2
(the Day of The Dead) to receive offerings from the living.
So, in the hope they'll come to your home, you lay out
food and drink, light candles etc, and aim to show them
a good time before they head back whence they came.
Imagine the dead and the living exchanging memories.
The nearest we have to that in New Zealand culture is the