They saw that they were naked. They hid, because they were afraid.
That is the result of eating the apple of the knowledge of good and evil: self-consciousness. Before, the sinless natural man does his thing, at unity with himself.
Or, before the natural man obeys God, doing as God sees fit, though capable of disobedience; disobedience breaks the bond with God, creates fear and separation.
A wonderful story, dating back to the exile in Babylon, 2,500 years ago- probably not to the time of Moses. Bibliolaters dishonour it by taking it literally. We have two ideals to strive for in the religious life: a life of obedience and submission; or a life of simply doing my own thing, without over-thinking, without internal conflict because it is Natural. Perhaps, they are both the same.