As infants we would have been bombarded with all kinds of sensory data. To make any sense of this world, we had to learn to screen much of it out, and this we started to do, very early on. Sounds, feelings and visual information that affected our little bodies and therefore our very survival, we tuned into. The rest, we learned to filter out. That goes for the sound of the freeway two blocks away as well as Dead Aunt Bessie in the corner, cooing at us, now and then and then vannishing. Not important; tune it out. Mom who picks us up and feeds us: important. Brother who moves fast and smacks us now and then when nobody is looking; also important.
Have you had dreams of a departed loved one? If so, this may well have been a Spirit Communication. Why are some of these dreams unpleasant? Only because your own fears and sorrows got projected into the dream. Your loved one had no intention of upsetting you with contact; quite the contrary!