It shouldn't happen? Actually People trip out smoking bud all the time.
It's happened to me a few times where I got paranoid, and it happens to even the best of them (ok maybe not the best of them).
It is normal though.
Naa I usually just get high but keep all my senses. Perhaps my thinking slows down and I start to think a lot less and become more focused about certain stuff. Then sometimes I start to think really deep and can't fathom anything around me. But what always happens is my mind and speech become out of synch and I talk not too intelligibly.
This is the usual occurrence but that day I just tripped like mad. The room was spinning, I had this little window open and my whole sense of gravity at that moment told me I could plausibly be tipped through that window so I kept grabbing things to hold on which is strange. I don't usually get high on my own but usually I'm okay but this time I was really paranoid as well and my eyes I kept believing were falling down my face and I could see bruising and stretch marks from them drooping. Suddenly I begin to feel sick and my head starts throbbing and my forehead starts burning along with my eyelids and I just couldn't handle it. Usually I'm very calm about these kind of things and I'm always prepared for the paranoia but this was the first time I ever got it. Now I'm not just tripping but I'm having an anxiety attack and there is nothing worse than being paranoid, telling yourself to snap out of it and being unable too because you're fucked then. Because you're looking at things logically and you still can't snap out of it, physiology trumps psychology I came to the assumption of.