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.
Ten powerful magic rings created by an Archmage have scattered to ten random people (suggest only one is PC). This happened when he died in battle. Whoever gets all ten rings inherites all the power the Archmage invested to them over his 200 year life.