You know, that is one thing that I did notice. I heard lots of people talk about "bad LSD trips". And I did acid a lot, one time eating 7 hits, and I never had a "bad trip". I was always just going with the flow.
The worst experience I ever had on drugs was one night when I was tripping on acid, I snorted a couple lines of coke. It was the first time that I ever did coke, and I just really didn't like the way that it made me feel. I felt super aggressive and felt like I had a lot of built up energy.
So, I made myself puke, knowing that it wouldn't get the coke out of my system, but it made me feel better. I think the whole thought of my body evacuating, tricked my subconsious into thinking that I was getting rid of the drug.
Then I waited a few hours and took a hit of x to get my mellowness back.