In psychology we learn one simple truth by which all the universe is ruled: there are no rules. That is fact, and there is nothing you can prove against it. Anything could happen and anything could be with no explanation or any logical reasoning or science or religion. Let me bring this more down to Earth to explain it.
Turn to the nearest living creature, preferably a human but a cat will do (I recommend it not be a fish. They are quite slimy.), and touch them. Press your finger hard on their flesh, just to be sure that you can feel them. Feel just how solid they are, this being. Feel how warmly they radiate. Imagine and experience just how much space they take up in your room (or you in theirs.)
That person is not real. They are not sitting beside you, looming over your shoulder, or scoffing at your "inane psychedelic nonsense" from the other corner of the room. They have never spoken to you, about you, seen you, been anywhere without you. They are not real. No other living human being on this planet can experience their existence. This being is solely yours. Every conversation you've had in regards to this person has not happened. Not as you remember them anyways.
Imagine that you have gossiped about this individual most recently. To you the conversation was quite fluid and constructed, but to the person with whom you were conversing it was a confusing and startling experience. In reality you were not conversing with anybody. If your conversation was over the internet, it might startle you to learn that the individual to whom you were IMing actually blocked you several years ago upon first learning how intense your dimentia was.
In reality you aren't even reading this post. Nor sitting in your home, or the library, or the school. You are, in reality, sitting with your arms crossed and tied in a padded room, bobbing your head side to side and being spoon-fed every meal by a grumpy old woman named "Martha" who happens to have a gardenous mole on the left side of her chin. This is your wake-up call. I am the aspect of your mind which understands that the life you have lived has been and is a lie. Return now, sweet child. Return to your senses.
Confused? As you should be. As I knew you would be. You are not yet ready to accept the reality beyond your own, and that is for a very simple reason: it is not your reality. The science and laws and people and world that you know are all created by your mind. Your perception is the very foundation of reality. If you perceive it to be real then to you it is. And what reality matters more? The one you don't exist in, or the one that you do?
In the end it makes you wonder, staring up at the stars at night: all those people say nothing is out there. They say this and that about the universe. Physics works like this, gravity works like this. But that universe isn't real. None of it is real.
That's the simple matter here. Nothing is real. All the physics in the world are only real... in this world. The one I experience. In this world gravity works in such a way, and people believe the universe is ruled in such a way.
But how do I know those people are real? How do you know I am real? You don't. You can't. I don't even know if you're real. You may not be. It might be that I am simply the last of my kind, creating a world full of people to fill the void. Maybe I'm not even human. What is a human, anyways? What do we look like?
I'd ask you to prove me wrong, to prove to me that everything I experience exists beyond myself. But the simple fact that I would perceive your answer means it could have all been created for me, in my had. Or I created for you, in yours.
Take it for what you will. Be what you will.
More important: don't scoff at beliefs you don't hold. Because the simple fact of is that no matter what aspect of the universe you hold to be true, it is all just belief. So get over yourself.
