Are "probability" and "truth" the same thing? It seems to me that we don't experience true things that "exist" but structure a world of symbols representing probabilities, like your map predicting the specific terrain. These are often so useful that they are mistaken for "true" and in many instances that will cause no problems.
But when I develop a habit of seeing models of reality constructed in my mind as "true" rather than related to specific experiences and probabilities, it becomes much, much easier to fall under the spell of those constructs, lose my ability to act responsibly, and open the way to great suffering.