Adam and Eve would have obviously known they were Naked - they did have EYES remember. But the first two people had just been created in their original state and so they were naked. Genesis 2:25 - "Adam and his wife were both naked, and they felt no shame."
When a child comes out of the womb, they are obviously naked. Does a child feel ashamed of being naked in front of their parents?
Job 1:21 - "He said, 'Naked I came from my mother's womb, And naked I shall return there The LORD gave and the LORD has taken away."
No, in fact a person is naked a lot of the time in front of their parents at a young age with no shame whatsoever - it is not that they are UNAWARE altogether that they are naked, it is just there is no shame of it.
God personally joined the first two people together and made them husband and wife - in the very first ceremony of marriage performed by God himself; a special union between specifically a man and a woman which is sanctified by God. (gen. 2:18, 2:24 - That is why a man leaves his father and mother and is united to his wife, and they become one flesh.)
When the first two people sinned it was not that they became aware that they were naked as such - it was that they became ashamed of their nakedness for the first time.
Genesis 3:7 - At that moment their eyes were opened and they suddenly felt shame at their nakedness. (NIV)
Most translation render the verse - 'they KNEW they were naked".
In the dictionary, the word 'knew' is described 'to be cognizant or aware of'. http://dictionary.reference.com/browse/knew?s=t
A husband and wife need not be ashamed of each other when they are naked and also a new-born is not ashamed of being naked in front of their parents. The opposite however is not the same - it is considered a disgrace for a man be seen naked in front to his mature children as we learn in Genesis from Noah and Ham's Incident: Genesis 9:22 - "Ham, the father of Canaan, saw his father naked and told his two brothers outside. (23) they walked in backward and covered their father’s naked body. Their faces were turned the other way so that they would not see their father naked."
So was God naked in the garden TOO? NO he was not!
We are told God wears clothes; specifically a white robe - whiter that the whitest wool:
Daniel 7:9 - "As I looked, thrones were set in place, and the Ancient of Days took his seat. His clothing was as white as snow; the hair of his head was white like wool." Mark 9:3 - His clothing was dazzling white, whiter than anyone in the world could bleach them. (Also Rev. 1:14).
God also wears sandals! Yes, God himself (YHWH) walked around his garden in sandals.
Psalm 60:8 - "Moab is my washbasin, on Edom I toss my sandals..." (also psalm 108:9).
Clearly it is not appropriate for a persons parents to expose their nudity to their children in their mature years.
Adam and Eve would not have remained naked forever, it was simply because they were man and wife and they were the only two living people in the world so there was no-one to be ashamed in front of. Once Adam and Eve had their first son, they would obviously have made clothes for themselves.
It is SIN which causes shame - not nakedness itself. Revelation 3:18 - "I advise you to buy from Me gold refined by fire so that you may become rich, and white garments so that you may clothe yourself, and that the shame of your nakedness will not be revealed."
It was only their shame which made them want to cover themselves up in front of God, because shame was something they had not experienced before.
Isaiah 47:3 - "Your nakedness will be uncovered, Your shame also will be exposed; I will take vengeance and will not spare a man."
Nakedness need only shame a person who is of sin in front of God or an adult in front of their mature children or in front of other mature people and their children. A husband and wife by themselves need not be ashamed at their nakedness in front of God, nor an unmarried person by themselves...