Schizophrenics have a whole lot of trouble telling the level of abstraction of a story. They're always biased in the direction of interpreting things more concretely than is actually the case. You would take a schizopohrenic and say, "Okay, what do apples, bananas and oranges have in common?" and they would say, "They all are multi-syllabic words."
You say "Well, that's true. Do they have anything else in common?" and they say, "Yes, they actually all contain letters that form closed loops."
This is not seeing the trees instead of the forest, this is seeing the bark on the trees, this very concreteness.