Well, we have to make a few assumptions first. I don't know for a fact that humans even experience anything anyways, all I know is that I do. The only way to truly know if there is anything beyond our comprehension is with a non-human who can communicate to humans. A.I.? Maybe, but we're still operating on our plane. I try to avoid defeatist mentality as much I can though, so let's examine. What does it take to make an A.I.? A programmer. Actually, if anything, all computers are operating on the principle that objectivity, as in what we can sense, is what is, which we can say we don't know conclusively that that's the case, only that logic is the only determining factor for complete thought.
If we assume and act as though truth is found outside of our feeling, we actually get pretty far. We can specify where our minds originate from, how we came to be, what happens if we do a certain action etc. And because operating on the assumption that existence exists and is outside of us, we can obtain logic without even trying. It's already there. At this point, we're still on an assumption, but at least its coherent. What about science? The scientific method is perhaps the best source for why this assumption has merit. Under science, assumptions are only met with the most stringent tests, and when those assumptions are concluded with coherent results, we assume its truth, i.e. evolution, gravity, cell theory, etc.
Okay fine, but how do we define what this reality is and where does it stop if it is "everything," what even is "everything." Hmmm, now we have a real problem. Well first we need to find if existence is a dichotomy or a spectrum. We really have no way of answering it per se, other than what we experience. We only experience a dichotomy of reality right? We might have to conclude that. Doesn't mean there isn't anything outside of it, only that it's outside of our comprehension, making it non existent in our terms. What we
can comprehend is something telling us that something's outside of our comprehension, so the thought exists, but not the actuality of the statement. What we're
not saying is that humans are the only way the universe can exist, but merely that we abstract and define the terms of it.