“Conscious experience is at once the most familiar thing in the world and the most mysterious.”

Source: Kitchen

In this work are exhibited in a very high degree the two most engaging powers of an author. New things are made familiar, and familiar things are made new. ~ Samuel Johnson, "The Life of Alexander Pope" from Lives of the English Poets (1781) http://www.gutenberg.org/dirs/etext04/lvpc10.txt
Misattributed

Variant: That is the true experience of freedom: having the most important thing in the world without owning it.
Source: Eleven Minutes (2003), p. 97.
Context: In love, no one can harm anyone else; we are each of us responsible for our own feelings and cannot blame someone else for what we feel. It hurt when I lost each of the various men I fell in love with. Now, though, I am convinced that no one loses anyone, because no one owns anyone. That is the true experience of freedom: having the most important thing in the world without owning it.

A Happy Death (1971)

§ 129
Philosophical Investigations (1953)
Context: The aspects of things that are most important for us are hidden because of their simplicity and familiarity. (One is unable to notice something — because it is always before one's eyes.) The real foundations of his enquiry do not strike a man at all. Unless that fact has at some time struck him. — And this means: we fail to be struck by what, once seen, is most striking and most powerful.

As quoted in The Oxford Dictionary of Quotations (1941) by Alice Mary Smyth, p. vii
Context: The most familiar quotations are the most likely to be misquoted. Some misquotations are still variable, some have settled down to false versions that have obscured the true ones. They have passed over from literature into speech.

Source: Books, What's So Great About America (2003), Ch. 6: America the Beautiful

Source: The World As I See It

De Abaitua interview (1998)
Context: A god is the idea of a god. The idea of a god is a god. The idea of Glycon is Glycon, if I can enhance that idea with an anaconda and a speaking tube, fair enough. I am unlikely to start believing that this glove puppet created the universe. It’s a fiction, all gods are fiction. It’s just that I happen to think that fiction’s real. Or that it has its own reality, that is just as valid as ours. I happen to believe that most of the important things in the material world start out as fiction. That everything around us was once fiction – before there was the table there was the idea of a table, and the idea of a table before tables was fiction. This is the most important world, the world of fictional things. That’s the world where all this starts.