I am not my brain. By meditating one can learn to go to the within inside of one’s self and as that experience grows it becomes quite clear that you are not your brain.
But I like the little zen story that tells it best:
The little fish went to the queen fish and asked, I have always heard about the sea, but what is it? Where is it? The queen fish explained, You live, move and have your being in the sea. The sea is within you and without you. You are made of sea and you will end in sea. The sea surrounds you as your own being!