I have noticed that sometimes the way a person thinks when they are really high on weed can look a lot like the thought patterns of someone who has schizophrenia. Both experience a sense of confusion, where normal ideas start to feel jumbled or out of place.
For example, when someone smokes a lot of weed, they might suddenly think everyone around them is talking about them or planning something. This can be very similar to the paranoia that some people with schizophrenia feel, where they believe others are out to get them or that strange forces are at work.
Another thing I have seen is how both being high and having schizophrenia can make it hard to tell which thoughts are real and which are not. Weed can spark daydreams that feel incredibly vivid, almost like mini-hallucinations. People with schizophrenia also have vivid hallucinations or beliefs that do not match reality. Of course, these are not exactly the same experiences, but the feeling of being trapped in your own mind, unable to separate real from unreal, can feel strangely similar.
There is also something about the flow of thoughts that ties the two experiences together. A person who is high may jump from one idea to another without much connection. In schizophrenia, this can show up as disorganized thinking, where the mind leaps from thought to thought in a way that is hard for others to follow.