This is the earliest dream I can remember.
As a child of three or four, I dreamt I heard a curious sound emanating from the basement. The sound from the basement was exactly the sound one hears after flushing the toilet: the streaming of water through the pipes to fill the tank. It was dark, night, and I was alone. A four-year old child, I stepped cautiously down the first turning of the cellar stairs, to see what spectacle was making the sound below.
I peered through the angle between the ceiling and steps, and beheld a most horrendous sight skeletal beings were streaming back and forth, impelled by some mechanical apparatus at their feet. Immediately I awoke in terror.