Bad part is you can go nuts, and this can last for many hours!! Can't tell what'll happen till you take some.
For any readers of Dune, the Reverend Mother mentions a place in her mind she can't go to because it's terrifying to her. Psychedelics can lead there without an individual's defense or consent, if that makes sense. Some people just aren't set up for tripping
This is me in a nutshell. Fortunately I've always known this and swerved anything like that. Some mates gave me some strong weed one time and that blew the lid off one of my 'secret compartments' and gave me paranoia for a week. Another mate of mine did acid once and although he didn't have a bad trip he lost faith in his own perception for about 3 months and wasn't sure what was real and what wasn't. Another of my friends did a load of acid at college and now has permanent schizophrenia. Scares the shit out of me. Yet another one of my mates, who is actually one of the most sensible and headstrong people I know, has done most of the recreational things and can just observe and compartmentalise it with seemingly no ill effects. Me? No way. It would be a one way trip for sure. I reckon I'm halfway there without being under the influence of anything at all!Hehe, the idea of dealing with some of my issues from the last 50 years under that influence... no thank you.