[elihu]

I think that's actually something that movies and video games have in common. If you find a random key in real life, it's very unlikely to be useful. If you find a key in game while exploring a dungeon, you can be pretty sure there's a locked door you'll want it for somewhere later on.

(I remember an old blog post Eskil Steenberg I read years ago about game design and procedural generation that talked about this; specifically, about the difference in the feel of the game between making sure there's only one solution to every problem, or allowing for some degree of flexibility so that the player is sometimes able to achieve their goals in unexpected ways.)