I quote:

Man [sic] could be compared to someone who lives in the Grand Canyon, but who is so short-sighted that he cannot see more than five yards. Or to someone who lives in a cathedral, but is surrounded by a kind of curtain, like a fortune-teller's cubicle, that goes with him wherever he walks.

The curtain is "everydayness". It is a state of mind rather than an objective reality.  The human mind must be thought of as being akin to the radar of bats; we somehow reach out and "feel" the reality around us. But in my ordinary, everyday existence, I do not need to "reach out" very far. And I get into the habit of not doing so.

Whenever I am deeply moved by poetry or music or scenery, I realise I am living in a meaning universe that deserves better of me than the small-minded sloth in which I habitually live. And I suddenly realise the real deadliness of this lukewarm contentment that looks as harmless as ivy on a tree. It is systematically robbing me of life, embezzling my purpose and vitality. I must clearly focus on this immense meaning that surrounds me, and refuse to forget it; contemptuously reject all smaller meanings that try to persuade me to focus on them instead.

—Colin Wilson, The Occult

I must add, for what it's worth, Happy Halloween! May your bags bulge with chocolate!