It is useful to have a trail map when you hike unknown territory. It will save you from getting lost at dusk or falling into an abandoned well. When I become familiar with the territory, I’ll know the trail is not the territory, and I’ll start to communicate with creatures in the woods.
DSM V is merely an incomplete and tentative trail map of the vast and unfathomable territory of our psyche. I hope your therapist is willing to communicate with creatures in the woods without getting lost.