Well, the real life savant which inspired me on this post does not forget music he has heard and can replay pretty much anything he has heard after the first occurance, so I did not see this as being too game specific.
One can forget specific details of spells and cause spell casting to fail so this can be applied to pretty much any system - for non-dnd it would mean his chance of succesfully casting a spell becomes higher.
I tried to avoid any specific game references and thought this was oblique enough not to set off alarms. Go to Comment
The player characters, experienced and somewhat well known, hear rumors and travelers' tales about a distant area being overrun by dragons (or other terrifying monstrosities). The locals have sent them a message, begging for heroic aid.
When they investigate, they discover that nothing of the sort is going on. It turns out that a group of thieves wanted them out of the way so that they could rob them (or someone who would normally receive their protection).