Monsters are kinda retarded...

[SiamJai]

Like when the music dissapears you know he is gone and you don't have to be scared cause he never spawns twice at same location

That's not entirely true. In certain areas (the prison for example), there is a chance that a monster will spawn more than once, even if you've encountered it there already. You just got lucky.

Overall I agree with you though that the enemies are less important here, and for that I'm actually glad, since it makes the exploration more enjoyable.