Just imagine, while walking down the street, that you are actually walking down a neuron. It is hard to believe that you could be walking around inside your own head, while your head is actually sitting there on your shoulders, but believe it anyway.
So, you are walking down your neuronal pathways, but they look just like normal streets with normal buildings and people and cars and trees, some of which you notice and some of which you don’t.
You don’t notice the library, perhaps, because you are always looking at the bar on the other side of the street. Maybe you only see the “hot” girls or the “buff” guys, and you miss everyone else. Maybe you never see the nature creeping out of the cracks in the sidewalk or the sparrows in the grass. But it’s all just landmarks upon your neurons.
What you decide to notice in the outer landscape is how you determine what is in the inner landscape; and, vice-versa, what you decide to notice in your inner landscape determines what you notice in the outer landscape.