Giving NPCs memories can go a long way to making a more realistic and enjoyable game world.
This is not a submission about creating NPCs, this is about presenting them. Not everyone walks around with a different accent, strange tic, or catchphrase, our memories are what make us different.
"...The people of the Dalaben Fens have a custom heretical to our superior Zodashan faith, in which they place their dead upon the grass roofs of their stilt-houses. It is said that they do this because they used to bury their dead before the great Judgement, in which their home became the swamp which it is today."-Sir Edrosh Metorva, "The Barbarian Lands of the East, Volume X."