I don't know why this happens. But I can relate to it somewhat. In my case, I know I do dream. But I seldom remember any of them anymore. (I'm an older person & I've wondered if perhaps, in my case, it's a symptom of old age. But I really don't know.) I recall reading somewhere, a long time ago now, that everyone dreams. We sometimes just don't remember our dreams. I don't know if that's really true or not. I suppose medications, psych or otherwise, might also have an impact on this. Perhaps other members will yet have some observations they can share.