Re: Are we real or only a game
Actually the OP here is entirely feasible.
The brain simply receives its information from the various sensory inputs we have.
What we deem to be sight and vision is simply an information stream being fed into the brain and the brain computes that info and enhances it, adds to it to form a complete "picture".
What we deem to be sound is merely the input signals going into the brain originating from the ear.
Everything, everything we think or imagine is "real" is in truth, just a load of signals travelling into the brain.
Once you get your head around that (pun intended) then you can contemplate the notion that you could take a human brain and hook all the sensory information wires up to a computer and feed signals in. The brain would likely not know the difference between those synthetic computer inputs from the real signals of body organs.
That being the case then yes, it is entirely possible that I don't exist in the way I "think" I exist.
I could in fact be anywhere, even be just a brain in a laboratory being fed false inputs.
In respect of such thinking one can surmise different ways that situation can exist.
One explanation is that beings voluntarily subject themselves to such false simulated inputs as a kind of computer game. if you like the very pinnacle of gaming where you are simply sat in a chair and in The Matrix style, plugged into a computer running a game of your choice. This game could be the ultimate mystery game where you are given the memories and experiences of something they call a human life and nothing more and you have to work your way through that existence to the point where you figure out that you are not real and participating in a computer game.
Another possibility is that it could be a form of prison or punishment. Those deemed a danger to whatever real society exists are perhaps strapped into chairs and plugged in to this false reality to keep them docile and locked away or perhaps to re-educate them.
A third possibility is that which is used as the plot in the film Vanilla Sky. That is that for people with massive disabilities there exists the option to be plugged into a limitless computer generated existence where they have no disabilities and can exist in a computer coma for years blissfully happy and totally unaware that they are in a simulation.
If this is all a computer simulation of some sort then t seems utterly incredible, but then it of course would because we would likely not have any memory of the true technologies of reality.