It's something that to me is associated with dissociatives (heh, I like that wording). They isolate you and put you at the center of everything, so what else could be the "controller" of what's going on in your head?
I've never thought "I am god" straight out at any point, but I've definitely had moments where I saw myself like a spider in a vast web of causality, sensing all the motions within it. I understand this web to be confined to my subconscious, and its strands consist of all these dreams I had never recalled in the first place, or fleeting reveries from months in the past -- amazingly random things -- and I get floods of memories from waking life that associate with them and explain how they fit into and explain the dreams to some degree, and in turn how the dreams affected my latter waking thoughts without me ever having been aware of it. After that, I feel as if I'm incorporating these realizations into my subconciousness to, among other things, be more fully aware of how they operate during waking life in the background of my thoughts, in reveries, in making judgments, and on and on, in order to expand my own awareness.
This interpretation does not seem implausible to me because it is entirely confined within my own life and mind. Moreover, gaining such understanding is one of the central reasons I use psychedelics and dissociatives in the first place. And so the idea that a consciously formed intention such as this should, over time and focused psychedelic meditation, come to be realized in the unfolding of a trip is somewhat expected.
But sometimes those dreams I remember are of recent world events. I can imaging conflating the sense that I am weaving dreams within my subconscious for the purpose of a deeper understanding of how they operate in my waking life with controlling world events like a god. For example, I dream about world leaders or climatological events and remember it while tripping, but all the while I'm feeling like I'm at the center of this nexus, and so instead of recognizing it's a nexus of dreams or long forgotten memories of my own, in my state of confusion I interpret them as the events themselves as they took place, or are taking place, or will take place, in physical reality external from my own past personal experience. Now, in my understanding, I become not a weaver of my dreams and memories, but of time and causality itself: a god.
