Ideas are always influenced by external information. That information is the base of our new creations (constructions). I personally think that is imposible to decide every element in a creation, even if you try to do it. It can be subconscious, it can be random, but it always dependen on our context.
Not just the creator is living under constant external influence, but the creations depends of the circunstances where the idea born. That´s why context is the base of every construction.