An accidental overdose of DPT. 40mg will waste me. I did a little over 60mg or so due to miscalibration of a scale (now I recaibrate between each and every dose of anything wieghed!).
I went to the other side, basically. I thought I had been born in the mental state I was in. I had no awareness whatsoever of being on drugs. I had to keep putting my hand under the running water from the facuet in the bathroom to keep alive (or so I thought). I was hallucinating so badly I could not really walk; the floor and ceiling buckled and swayed, shot out patterns of color into the air. It was terrifying, absolutely horrifying.. but at the same time a very interesting experience.
That description of my experience is like describing Olympus Mons as a big hill.... but I'm too tired to go into any detail.