I have done K about 60 times. The first 40 or so ranged from pleasant to ultimate insight and power to do anything. However, one night I did 15mg more than I ever had before (115mg having been my previous max.)
On this trip I visited *HELL*. Where I went was somplace nobody has ever gone or was supposed to go. Being an extreme risk taker I have faced death many times before; it has never frightened me. But, this went beyond simple death, dying in this place meant an eternity of torment that is not comprehensible in a non-K state. I did not nor do not believe in an afterlife. But, that experience was every bit as real as our 'normal' reality.
Here is my problem. Since that experience all my K trips have sucked. Nothing transcendental happens anymore. I just go numb and my mind wanders a little bit but nothing else happens. Except this, now I *always* get up and walk around at the apex of my trip. So far I have not been able to stop myself from doing this.