At age 17 I had the common experience of dreaming of my recently deceased mother, but my brain didn't take long to realize that seeing her was not possible, and I realized it was a dream. For some years I kept that ability to quickly see the inconsistencies in the dream world, but as of now my asleep brain is back to normal gullibility. Because I have a strong preference for living in the real world, I very strongly (verbally, actually) forbade my mind from showing me my dead mother again, and it obeyed.