Let's compare.
Average mushroom dose: Free-floating mind. You can generally fade in and out of whatever you want to, and it's a hell of a ride but it seems more choice oriented. However, it will always be intense regardless of what choices you make.
High mushroom dose: Free-floating, but the more the trip changes, the more confusing it can become. Focusing on one thing and just immersing yourself in it usually ends up in speechlessness, drooling, intense fixation and enjoyment. Getting frantic, i.e. jumping from conclusion to conclusion, brings on a bad trip.
Average LSD dose: Mind tends to focus on many things but comes back to the central idea of some sort of enlightenment or teaching. It seems as if you feel resolved about everything, and you notice each thing individually.
High LSD dose: Mind wanders still yet and it becomes hard on your cerebral transmission, shifting between all this information, so you try to stay at rest. If this resting period is given too much attention, you can focus and completely lose relaity in that one idea or thought.
Personal High-Dose Experience:
I was in the desert, late 70's. It was nighttime, I am just about fully peaking on a third of a vial of LSD, and there is a 20-foot-tall fire a hundred yards away. This fire grows into the sky and scorches the entire earth.
Before I know what to do, there is a light surrounding me like day. I become hot, almost burning up. I take off my shirt. I can tell I am breathing heavily. The sand around me turns to water and slowly rises to my shoulders. I feel bound into the sand, as it rolls like the ocean in front of me.
The fire is as burning hot as the sun, and I can feel its extreme radiance on a cold desert night that is anything but night at this point. My buddy is walking over to me. I gaze at him, wide-eyed and panting, and he begins to melt as he walks along, his shirt, hair, and arms dripping off. I attempt to run over to help him out of the heat but I realize that I too am melting into the sand. The heat is so unbearable at this point that I feel I am going to die. Wait, I am dead. This is death.
A loud buzzing noise eats at the inside of my head. I look up to see a rock, and then it has wheels, it is a vehicle. I feel a wave of sand finally wash over me and pull me under.
Truth be known, I had just stumbled face-first into the sand. I was told that I screamed so hard it sounded like I was choking on the sand. I sat back up and I remember very clearly seeing the most beautiful purple fire ever, and I felt cool and refreshed. But my mind was so incredibly blown that I just sat next to the buggy and stared at the fire.
After I got calmed down me and a buddy took a walk into the darkness, and I lost him on the way... Everything went dark and I remember walking for what seemed like several years towards two headlights of the buggy.
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Why do people fear LSD? Because it deserves that status. LSD is a powerful psychedelic. There is nothing in this world similar enough to LSD to be considered so. Nothing can destroy your mind into the state that LSD can. Sure, there are things that are more intense, but LSD rips apart reality in front of your eyes, and you can't do anything to stop it.
I have never tripped on anything that made me believe, while only for a short time, that the world was on fire and I was swimming in a lake of molten sand, melting as I went.
--mic