See this article for a fascinating discussion of inattentional blindness: Inattentional Blindness and Conspicuity
It says in essence that our mind discards the majority of things we perceive before they reach the conscious mind so that our conscious mind is only presented with relevant and important information. The problem though is that sometimes we miss the important even though it is in plain view and the article gives many examples of this. This is called inattentional blindness.
So my question is this: does the same thing happen to photographers and does the same process prevent us from seeing fresh photo opportunities. If so, how can we break through this barrier so that we keep our vision fresh and alive?