A true nature is a gloomy monolith, sort of like that old...

A true nature is a gloomy monolith, sort of like that old black rotary phone that I had to sing 'Happy Birthday' to Grandpa on. But novelists, damn us, still need true natures - so we can give them to our protagonists. And so readers can vaguely predict how they'll behave when we trap them in 'situations' that they can't IM their way out of.