The reality in the brain is only those sensors triggering electric impulses and our "thoughts" being processed by other electric impulses. Reality is just some electricity.
That doesn't make for a very good story. The Matrix reminded us that everything we know as reality external to that electricity could be wrong. That makes a fascinating story.
We live inbetween those two extremes. Short of the matrix, it is possible that each one of us has a different reality. My sense of "red" may be completely different from yours. We never would know because it's total reality to each of us.
But my sense of red being slightly or even greatly different from yours doesn't make a hill of beans of difference to our realities. When we talk reality, we talk of the human experience. Children starving in Africa or earthquakes in Japan are realities. (Positive things too, but I don't want to digress into something else.)
Our human experience on this board has hugely to do with our human experience with our brains' realities. Many of us thought we were the only ones (as JW's) that saw reality that was being shielded from "the world" by Satan and his minions. It turns out that our brains were being deceived, just like the matrix. Only, the rest of the world wasn't in the matrix we were in, for it wasn't Satan deceiving THEM, but it was Watchtower deceiving US. And it wasn't physical reality that was withheld from us, it was "thought" reality or "belief" reality.
I think this is part of why we are pained or disturbed so much. We had to take the red pill and discover that nothing in our own brains was really so. Then we had to admit to the world that we were deceived, not them.
Dreams don't make us admit our deception to others, nor do they typically cause us to take the wrong life path down a false reality. It could happen, but generally not so. Dreams deceive us only for a brief moment then we wake up. I am of course refering to literal dreams. We should not confuse that with figurative "dreams" of goals and wishes and enjoyment in life. They are a huge part of our reality because they are the things that cause the positive electricity in our brains.