It's related to the mismatch between the child's understanding and the level of the questions. That is my opinion, anyway.
This has been a terrible problem for DD all throughout school (grades 3-12).
While it waxes and wanes, it seems to be tied to low-level cognitive tasks. She just doesn't think on that plane, and hasn't since she was 3 or 4, so asking her concrete questions like "what is a star?" mostly elicits PANIC from her...
because she's thinking "do you mean SCIENTIFICALLY?? At what level? At the level of the reading selection? So what is that.... about fourth grade? Sixth grade?? What do sixth graders know about astronomy, anyway?"
Er-- or does it mean the metaphorical use of the word "star" in this story? Can I give more than one definition??
AUGHHHHH!!!
Never fails.