There is no projector Joint N-11 Review in your head showing a view of the outside world on a screen at the back of your skull. Nowhere in your brain is there anything that looks even remotely like what you see through your eyes. All your brain has in it is a load of neurons brain cells that are communicating, or not communicating, with adjacent neurons.
The communication takes the form of messenger molecules neuro-transmitters drifting across the synaptic gap between the axon of one neuron and some part of the next neuron. Yet we see what seems to be a very real physical world. But we are making it all up. The brain somehow deludes us into seeing outside of us, what never exists inside of us.