I believe that Thagomizer has a point with his description of the tree of Knowledge.
As little children, we are not very aware of our egos. Then one day they jump up and bite us in the forehead. Now what are we going to do. Many will stay in a state of nurturing this new found I'ness for the rest of their lives. A few, a very very few will start looking for a way to get to the Tree of Life. Even fewer will find it.
I don't think that staying in a childish state is very protective or wise.
I think that it is childish.
I don't think that we are supposed to be childish forever.
I think we are supposed to be cocreators.
Sin is something we tell people to be afraid of so that we can control them.