Interactions as manifestations in the mind.

Reality Questioned:

Cognition enabled by Electrical Impulses (Action Potentials)
in the neural networks in tandem with neurofeedback
 in the Brain creates Consciousness. 

It is a good question as to ask "how do I know If I am real, and what if all matter==mind?"  or if all interactions are manifestations in the mind through information from the senses.. It is through the experience of other mind's creations and their activity that interacts with mine that makes me believe it to some extent. However even this feeling could be evoked for a brain in a jar, for eg a brain in a jar which can receive and process wireless signals from a source, the source needs to know what parts of the brain to trigger and activate to simulate consciousness and the source of signals also needs to know how those signals look like for flawless simulation for the brain in the jar, in order for it to do that it needs to be coded or translated at least from a REAL physical brain, (like transferring software made on one system to another system with the same architecture) so maybe now I can confirm at least the fact that another brain exists on which I was written or expressed and it helps in simulating mine.

Simulatable Universes:

Structure formation in a computer-simulated Universe covering a dynamic range of a factor of 10000 in linear scale.
Can it give rise to structures we see around us?
Image courtesy of  Virgo Consortium

Now to ask the question, if that complex brain which can create such a powerful flawless simulation of me for me exists, why not it just be my own, wouldn't that be just more efficient to make it absolutely flawless? (this is where Buddha asks the question and wants to dissolve the "I exist" notion and make it one universal entity)  Therefore now I confirm the existence of mine through an induction of the existence of another (but this induction is also refutable like Buddha wants it to be). If everyone has the right to claim that their minds exists using this route then we might as well have everyone existing in interaction, proactively in experiencing this co-op video game using their systems to simulate their individual worlds. The brains still exists, which does not necessarily include the whole me. However we have the same descriptions of the worlds except in complete psychotic cases (like playing an First Person Shooter with different levels and worlds for each person playing in the co –op etc) and seeing how interesting it gets... The key seems to be to not search for meaning. However I like to think of us as probes to testing this idea as to why atoms itself were brought into being to create brains however brains exists a priori and hence it doesn't make sense to question the creation of the sub domains of the created, similar to the case of you or I having already been born and then and only then being capable of asking the question as to why we were born in the first place.

10 billion particles to trace the evolution of the matter distribution in a
cubic region of the Universe over 2 billion light-years on a side
Image Courtesy : Max Planck Society's Supercomputing Centre  & Max-Planck-Institut für Astrophysics

Provoking Anthropomorphisms:

If this is a random accident or just a running experiment, this is where the  anthropic principle comes into picture which says that its only because of the occurrence of certain environment that leads to the birth of sentience with which we can ask that very question. So there needs to be an environment (something real) that precedes the ability to ask such questions and thought itself, hence the environment is real and If I am the product of a real environment, I am real as the thought and the sub domains preceded my existence! The next possible question would be to ask if it possible to run a simulation without a physical engine to run it, which seems slightly implausible even for dominant futurists in the field. If so then where, how, and with what is the simulation running, who is running it (does SOMETHING need to run it or does it self propagate and if it does self propagate which laws provide it the motivation to do so )? This I suspect we cannot know. The game of life is way easier to play and manipulate. 

Still from "The Thirteenth Floor" suggests how computer scientist
could end up discovering the laws of simulatable universes.

The '13th floor' Inspired argument:

Okay let's look at it this way, you're here now to ask the question as to if this is a simulation if this is real or not if "matter==mind", lets say we assume it is not real then in principle you could be driven enough to break the simulation and show others how to since you don't know its ultimate purpose, but if a simulation is smart and powerful enough, why would the very simulation allow you to know and understand how to break it? If it has a (hidden devious) purpose to imprison you, wouldn't that be detrimental to the whole simulation's continued functioning? If something-someone gives you the ability to ask if its real, then that something must be dead sure of no giveaways, the universe gave us this ability to question it and its purpose or whatever made us is quite sure of its physical existence to make sentient beings able enough to question it and test it, If it's not real and we are being fooled to think that it is at some point we all will break it(agreed). This, the universe will NOT allow if it knows we possibly CAN at some point, so you are imprisoned in this game till you are alive. However it also allows us to do exactly that if we wish to, so far (we can destroy the entire earth if anyone amongst us wishes, can't we, if earth is like a big system of imprisonment). So all I'm saying is that the universe is either pretty strongly sure that we can't break it and is asking us to bring it on. Either way you have to play its game. There is no escape except death which you'll invariably prefer to get in the end. Play well & enjoy it meanwhile I leave you with this quote from Professor of Physics, University of New Hampshire!