I believe Akihiro, as I also had the same experience. I didn't experience it in a dream, nor did it haunt me. It occurred in kindergarten...but these thoughts were feeding me, giving me my lucky spoon...etc.
I thought my conscience was the "only" one--all else was just a set of actions from others and environment as predicted in my thoughts. I did not recognize the consciences in others--just my conscience, all else just fed it or affected its perceptions. For some time, I thought that this "all else" that affected my conscience were simply thought products were my unconscious. I used to have nightmares almost every night until 5th grade---not "scary" nightmares...but peculiar and strange ones whose environment, although not logically plausible, that evoked certain memories at times during my life (i had very accurate memories during those times--even after book/science reports from fourth thru eleventh grade...i remember the pictures, texts, paragraphs, and captions from the textbooks--from math averages..etc..etc)...memories that were confounded with fears (religious, physical, mental, etc). These unconscious thoughts would be what "haunted" me, as possibly the dream of Akihiro. (Funny though...these thoughts turned up in my dreams!)
Until after 5th grade...I had no more such thoughts, and had a better grip on a more optimistic reality. However, no matter how fearful they were...I still seem to miss those perceptions; perhaps they evoked some other sense of nostalgia coded in unconscious form understandable only by the dreamer/perceiver, or were just perceptions of how I basically emotionally perceived these events in the waking world.
Similar to that of Akihiro, i also felt that my conscience was the "only one"--i.e., only I perceived "emotions" and was truly "alive", where all else was just minor perceptions and products of my thoughts.
According to Piaget, a child psychologist, it seems to be that such thoughts may be an advanced form of "egocentricism"--(for lack of better word?)...that only the child's conscience exists and only the perceptions of the child are real, somewhat speaking. I suggest that Akihiro read on about Piaget's view of child "egocentricism."--which i think was later proven false or not usually true--by a series of certain psychological experiments, such as this one (from "Psychology: Fifth Edition, by Carol Wade and Carol Tavris, page 503):
Whene a "3-year-old girl was asked to place place the doll where the policeman could not find him. According to Piaget, she should be 'egocentric' and therefore hide the doll from herself as well. On several occasions, however, she placed the doll where she, but not the policeman, could see him."
Although this is HIGHLY oversimplified and the child may be simple as well, it seems that Akihiro may have experienced a form of such "egocentricism"--where, in practicality, would probably repeat what the girl would do...but inside...may feel this concept of "egocentricism" (for lack of a better word?) where his conscience is only one...the only one with feeling or is truly alive--not a product of thoughts or concepts or predictions about nature/environment/other's actions...etc as everyone else
I thought my conscience was the only one and--well, the things written in my above post. I understood that others may well have had consciences as well, but was unable to sense or feel it, so I considered that only I had a conscience--or for a better term, only i had "free will"--everyone else was just deterministic (kind of like robots, but not exactly), where people would be predicted as products of actions, environments, and basically my current thought and intuition--where, what I currently thought was real. I accepted the existence of the physical world, but did not believe in the widespread orientation of "free will"--or so i think--but maybe it was something else--
(Well, I’ve pretty much faith in my sanity and I’m a normal boy! )
-as said by Akihiro
Well, that's my "two-cents"!
