From the same school of thought as, "Hey GM, which book did I just randomly pull from the shelf of the wizards' library?" No plot hooks here, just flavor additions.
Found, normally, deep in the swamp, the Friar's Weed's poison is something to be watched for.
A world where, instead of aging in years, the people age in knowledge. So, instead of dying once a general age was reached, they die once they achieve a certain amount of knowledge. A man could live forever if he never learned anything, or could die after reading a few choice books. Of course, the knowledge of the land would be regulated, like medical drugs.