One night in my younger days I was extremely jacked up on tremendous amounts of alchohol and a variety of narcotics. Nothing too abnormal during that period of my life however I did go a little extra harder that night. I was laying there completely put of it almost inept of function. I truly felt as if I began to die, it was as if my soul/consciousness was trying to leave my body, but I had to fight and "hold on" as thry say for a few minutes until that feeling stopped.
Tl;dr pretty sure I experienced the beginning of death.