What is so wonderful about good fiction is that it asks us questions about our concept of reality.
Confusing the two is extremely dangerous. If you don't know the difference, you are truely lost.
Or worse, if you think you can control it by force of will, you are dangerous. Think Malignant Narcissism
If you are not willing to face the idea that everything you are living is wrong, you cannot defend it aginst the concept that you could be wrong.
The question remains:
If everything you experienced, considered fact, believed to be true were shown to you to be without a doubt to be a lie, would you want to know the truth?