They had a whole new frame of reference...knowledge of good and evil. They were fundamentally altered by sin. Not only were they separated from God, but they were corrupted in every aspect of their being. Before sin, their inclination was towards God and they listened to His voice and desired and delighted in His company. After, they hid from His presence and made their own way apart from His word. They didn't retain God in their thoughts.
Everyone would have just known what was wrong.