I'd say a small dose of mushrooms (or LSD, but less experience there) is actually more likely to be a positive experience than weed edibles. Most people I know who have had bad experiences with drugs had it with edibles (or even just weed). Of course, due to the culture, weed is considered more "normal" in most countries than psychedelics, which is somewhat ironic in my experience.
To be clear, not implying that weed can't be wonderful or that you can't have a bad trip on psychedelics, just speaking from what I've experienced, seen and heard from others.
A psychedelic is in my opinion not an easy drug at all.
I don't think it is a normal experience for anyone, for the first time, to realize that what you see or what you believe can be influenced that easily.
While halos around light with lsd is nice to watch, its still a crazy thing. I never had visual impairment on that level from weed or alcohol.
Or when you see moving patterns on a wall, it does break one sence you as a human have a lot of trust for.
Our neighbor is an old lady who had cancer and apparently smells sometimes things which are not here. She doesn't want to be crazy and doesn't even accept that it can easily be nerve damage or whatever which makes her sometimes smell things which are not here.
Instead she thinks we and neighbors above her are trying to get her out of her flat. We are living in a very stable modern building, there is no realistic benefit of anyone to boot her out and walls are so thick, there is no noise issue at all. She still called the policies at least twice, had an expert here and was standing in our door twice angry and pissed of because we are creating that smell. It was 2 am in the morning and i was asleep.
Getting tired, not being able to walk well anymore, loosing concentration or forgetting things are apparently easy to understand and to accept as a human.
To be clear, not implying that weed can't be wonderful or that you can't have a bad trip on psychedelics, just speaking from what I've experienced, seen and heard from others.