Dreaming occurs nightly but they are not always remembered. The more painful the dream, the more likely it will be remembered and dreams can be painful indeed.
A young child dreamed repeatedly of being eaten by wild animals, and for an adult woman the dreams mirrored her continued sexual abuse when a child. Yet eliminating this pain is not rocket science since dreaming has long been understood. And despite their occasional discomfort, all dreams are our friends I tell my young patients. They are movies that we create in our mind to tell what is troubling us, perhaps being afraid of a school test or the like.
Interpreting a recurring nightmare, whether of a child or adult, will usually eliminate it. Unless the interpretation was faulty, or incomplete with there being more to the emotional conflict that it symbolizes with the person being unable to resolve it at that point in their life. An adult's nightmare that persisted for decades took three years and two interpretations to disappear completely, there having been important personality changes needing to occur first. The initial interpretation reduced the nightmare's frequency but a timely, second interpretation was needed to eliminate it.
There is a logic to nightmares just as with physical symptoms. A fever disappears when the infection is gone, as does a nightmare when the emotional conflict that it symbolizes is resolved.